I'll make one more response here because I'm at work and it's obvious we aren't reaching much of a common ground lol. I think about Tracer what you think about Winston, that she's not OP and should be changed but just that she's really strong in the current meta. I say that because she has gotten no changes since beta and yet her pick rate has been all over the place. That being said, I do think that Tracer players have gotten better with her over time and unlocked her full potential, particularly with how strong her pulse bomb can be in the right hands. There may come a time where she should be looked at for nerfs but I wouldn't go there yet.
Your second point is basically my above paragraph, although I will say that a hero's potential strength doesn't really matter if they aren't seeing much play. In a game with as few characters as Overwatch, a character's power level is pretty surface level in most situations.
I get what you mean that dive was already increasing, but if dive was already a balanced comp in the meta, wouldn't a huge Winston buff severely amplify the comp's power level?
I guarantee you all this talk will end up being pointless as Doomfist will hold Winston back anyway lol. That's the upside of having a lot of characters, there are more counters to keep specific heroes and team comps in check.