A few things:
We all want table tennis to be even more popular. If that's case we need to bring English into its marketing. Yes I agree that most of Ma Long's fans speak Chinese only. Yes I agree that majority of Hiya Hayata's fans are Japanese speakers. However, in what language are we communicating here? English.
There is no denying English is the medium through which mass marketing can be done. Not Mandarin. Not Japanese (although in the 1980's, with the Japanese economy in a huge bubble, we really thought Japanese were going to buy up all the real estate in New York City!). Not German.
Li Ning is a powerhouse sport brand in China. But don't think for a second they don't want their home grown athletes to be signed to Nike at some point (granted 10 years later, who knows where Nike will be but you get the point). Federer is making a load of money on his watch endorsement. Can you imagine if the Chinese or Japanese table tennis players can be marketed through English, how much more luxury goods endorsements they will get across the world?
Ma Long's speech (prepared) in English already generated so much buzz and those words can ONLY connect with the viewers when it is coming from his mouth. It is just not the same through an interpretor. Is Federer's English perfect? No but people actually like the way he speaks English with his own accent. Same as Ma Long. Was his English perfect in that speech? No, it is by far from being perfect. But it is his own voice. It is his own interpretation of the English language. It is his sincerity.
As for making table tennis more popular, there is the traditional way of trying to do it through local schools; we call that the grassroot movement. Unfortunately many countries table tennis federation and ITTF do not do much to grow any of these grassroot movements at all.
With the advent of outdoor table tennis tables being set at various parks and the social media movements (like at Pongfinity and Adam's YouTube channels), I think there are many more ways to make table tennis popular. We just need to be flexible in our thinking.
I would even argue that we should go after the adults who are the "basement" players. They can also become the future of table tennis. Let us be frank. The kids don't have money to buy the equipments. And table tennis equipment can get pricey. If the adults/parents get hooked onto ping pong, they will be the consumer of the various equipments (and become addicted EJ's) and they in turn will get their kids and their kids' friends involved in the sport.
It is a bit like in America, you can see people playing basketball outdoor, in the park, or at local YMCA's or gyms. They have 1-on-1 or 3-on-3 scrimmages all the time. They are not playing full-court 5-on-5 basketball at full steam. These are casual players. Those adults playing are a huge part of the global basketball movements. It is not just the summer leagues for kids that keep the sport of basketball going.
Table tennis, with its ability to be played at a small area and be a dominant indoor sport in parts of world where the winter is harsh, has a lot of potential.
One impediment is that there is a high learning curve to ping pong right at the get go which intimidates a lot of players new to the sport. By contrast, yeah, pickleball has a very very low learning curve in the beginning. Pickleball is spreading like wild fire across North America right now.
To overcome that steep learning curve, it takes experienced players at the club to be willing to hit and give some pointers to the newbies. I see a lot of snobishness at the clubs in North America. In addition, coaches are not usually involved unless private lessons are paid for. I don't think it is necessarily coaches' fault because they have plenty of things to worry about. But a few free pointers here and there by any intermediate or advanced player will do the sport much good.