Camera bodies are overrated, lenses are 10 times more important. I don't like to think about fanboys of any manufacturer, I like to think on each one of us wanting to spend their money on what we consider the best tech for our needs.
I use Canon since 1999, in the film days, and never had any other 24x36 system for this 26 years, so I can be considered somewhat a Canon fanboy, but no matter what the R6 III is bringing us, I can tell you I have never been so close so switch side, to Sony, and not by the reason of "lenses", plural, but I'm ready to switch just to get ahold of a single specific lens, the Tamron 35-150, that for me is enough to bear with Sony ergonomics and menus, which I deem way inferior to Canon's.
Cameras are full of marketing gimmicks, sometimes REALLY helpful, especially in the AF department, but in the end they're just black boxes recording light via the exposure triangle, and what really makes the difference is lighting, first, and the lens, second. Camera comes in as a distant third.
I don't know if Sony fans won't be able to ignore Canon after the release of the R6 III, but I can tell you that I still won't be able to ignore Sony even if the 45 f1.2 (which is why I'm here, the R6III doesn't interest me one bit) is great and even if I'll buy it on pre-order, I'll still be thinking about that Tamron lens, and possibly ending up switching side.
Who cares about being a fan of a company? Really?