This may be true, but is the addition of a Psion and perhaps a Witch, Warlord, and Shaman a "ton" of classes.One last time. Tons of classes just trying to fill every possible need simply leads to bloat, confusion, issues with multi-classing and niche builds that are broken. It was a major mistake of previous editions. A lot of the weight carried by new classes was removed by rules simplification and backgrounds so they aren't as necessary.
With 5E they're limiting to classes that make sense and fill in major gaps. We're not going to have the dozens of classes. We might get a psion. I think the odds of getting anything like your brawler is slim and none and Slim just left town. I think that's a good thing.
Is this your "slippery-slope" argument?
If I recall correctly, 3e's niche builds were a result of, say, dozens of classes and almost as many prestige classes, coupled with expanded feats spread across many, many books.
Is this really the same?