This is perhaps the one game in development right now that could release at any time this year, next year or the year after that and it would still perform incredibly well. It's pretty dead-set on being the largest entertainment launch in history. In other words: They can give it all the time it needs. The only worry from Rockstar's and Take 2's perspective is that they need to coordinate it with the behemoth of a marketing campaign that will be accompanying its release. There won't be a last-minute delay, but if it needs more time, they need to realize this months ahead. So far, it seems to be on track or else the CEO wouldn't release statements like these.

Since there is no PC release at launch and since it's only targeting four different hardware configurations for the time being (both variants of the current-gen PS and Xbox), they don't need to worry about making it run reliably on a wide variety of systems. Just like every other AAA developer, they are probably cursing Microsoft for releasing the cut-down Xbox Series S, but given what they have achieved in the past with hardware far less powerful, I doubt that Rockstar's tech wizards will have too much trouble with getting GTA VI to run on this affordable console.

You are right about crunch though. Rockstar is notorious for this, always has been. I hope they've learned their lesson by now, realized that all crunch does is make people burn themselves out for worse results, but who knows, given how secretive the firm is.