What kind of things do you ask them and how honestly do you think they answer? Will they talk about tactics willingly? Will they talk about their experience playing against specific players?
Also, not really related and I'm not trying to put heat on your or discredit you or anything, but what level do you play at now? I remember it being quite good (2200+?) but I haven't seen match video in ages.
I am usually USATT 1800-2100 depending on the day or weather and my ability to move. I don't play as frequently or consistently anymore, I try my best but age and injuries are still factors as well as family life.
Usually many players in America have different histories with serious training and exposure to high level table tennis players if they played in certain clubs or spoke to people at certain tournaments, the community here is fairly small. Speaking to a TT pro is not something special depending on what you consider a pro. For example, if you go to Westchester Table Tennis frequently, at some point, you will meet professional players. Many clubs in the USA have coaches who were on the professional players hierarchy of a country or club at one time or another.
Professionals come in various roles and levels and it depends on who you talk with, when you catch them and what you are talking about. Someone like
@Matt Hetherington is one kind of professional who is not the kind of professional you might have in mind. But lots of informed professionals or amateurs (depending on your perspective) like him also tell you things if you are a nice person and talk to them.
Because I am Nigerian, I have also had the opportunity to hang out with Nigerian national team members in various contexts. I live close to a school that gives scholarships to players to come and play for them and sometimes they get top players from other countries who are not as committed to TT but are still strong.
Some people might also remember I did work with TTEdge a while back. I consider them good people even if I don't work with them as frequently anymore for various reasons.
No I don't ask them about tactics per se, though some players/coaches can cheerfully volunteer what was working for them after a win or sadly volunteer what they struggled with (or even do both with various moods after any competitive result). I have seen 2000 level players give 2700 level players coaching during matches so it isn't always about playing level when coaching, a part of it is really just having something that makes the player feel better though obviously what you are seeing/saying may not be helpful.
I, with my personal perspective, usually want to see their equipment first and foremost and get their take on it or story about it. That is because it is the one thing about which people tell stories which are often uninformed lol and I prefer to get my own impressions. And they tend to tell me how they got it etc. Sometimes they don't always use stuff their sponsor would approve of. But they are the ones taking risks doing that. And whether they tell you that would depend on how much they trust you. If their sponsor found out, it might not be good. But who really knows, until you get really good sometimes no one has a chance to monitor you.
In any case I hope have been detailed enough to satisfy you. Most strong players don't magically appear from nowhere, they go through training at the junior levels and sit on the outside/inside of the junior national teams and national teams hierarchies. The table tennis community is fairly small, so you can talk to professional players or their relatives if you hang around it.
The current US men's national team coach for the US lives in Texas with his wife. I have done one camp with him but don't know him deeply but he and his wife coach a lot of players in the area. What do you need to know about table tennis that he can't tell you if you ask politely? He coaches Kanak Jha at national team events. The same is true for coaches like Larry Hodges depending on their interests. Its people who don't talk to any such players or who don't try to talk to people in all roles on the system that believe anything they hear. I am not saying that you don't pick up hearsay or second hand info in such conversations. In fact you do. But it is very different seeing a blade of a player which is not one his sponsor desires being used with the sponsor rubbers vs reading the equipment on the website etc.
Ady Sareen was growing up in NJ around the time I lived there - I was injured for most of the period he was coming up so I never had a chance to play him when I could beat him and then he was 2200 and I started playing him lol. His father (a 2200 player cold, former junior international for India I think) has good opinions and insights on junior development, you think if you speak to him nicely, he won't talk to you about what his experiences raising his son in TT are? Or that Ady can't speak to you about his game? These are just the prominent examples, there are lots of parents who spend money on training their kids in the US and these kids are not going professional. I even remember one very talented one who I used to beat as a kid, and then he got to like 2400, and then all of a sudden, I stopped hearing about him. and then I asked a friend who hangs around in similar circles (if you play a lot in NJ/NY/MD/DC/PA, you can enter that circle for free) and he told me that the kid had injured himself to a point where table tennis was no longer in the cards. Sad but it is what it is. But when people talk about coaching and proper technique etc., they tend to act like well coached players never have injuries, let's just say the story is never so simple, you might not know whether a player is doing something that their physical training doesn't fully support.
In any case there is nothing glamorous about it. IT is just conversations with people that you know as people.