Yes, mostly that has been true, but not entirely. For most of its history, Viscarias tended to be heavier (almost always in the range of 88-95 grams, usually >90), but there was a period not too long ago when there started to be a lot of very light ones on the market. Just a year or two ago -- the series made just before these green hologram ones appeared -- it was not unusual to find Viscaria blades in the 82-85 grams range, which is the same weight as the now-discontinued Viscaria Light that they sold for awhile! I suspect they were hollowing out the handle more and trying to make the blade more popular for non-pros or people who are using heavier rubbers. But I don't know that fore sure. (Also, I should note that some of the second series blades were thinner and lighter, but those are very old black tag ones rarely seen now, and personally I don't like those so much either).
A lot of the people who really love these blades (like me) find that ones that are that light feel very different, and not good; pretty much like it was a different kind of blade altogether! OF course this is all a matter of taste, but to me and some other people, these very light ones feel completely hollow. I have not seen any of the newest series (with the green holograms) that are that light. I think maybe they figured out that it was not a great idea. Actually, all of the green hologram ones I have hit with are good, kind of like my very favorite ones that were generally made around 2007-2009. (The production dates of these blades seem to affect the way they play. Is it because of something intentionally done, or maybe build at a different factory, or maybe different batches of wood? I have no idea).
I think from day one it was not unusual to find TB-ALC blades in the 85 gram range.