Cheers for the response, Dopey.
i know it doesn't exactly answer everything. OS stuff comes together at the end. Hard to get a sense of these things when we're hearing from devs when most or all launch software is gold and MS has turned all its resources into finishing the retail end of the platform. If November 22 rolls around and the issues are there. OK. Everyone fucked up. But from this we understand if you're playing a game in SP or MP and aren't using parties or apps... if you're using twitch, you're unlikely to be in a party... you may not really care if an achievement doesn't pop up. (even if it's still recorded) Most user experiences should be flawless.
the bigger thing is snap crashing games
snap can't actually crash a game afaik. They both run in 2 separate VMs and run in their own protected memory and their own CPU/GPU resources. Either there's a bug in the game/communication OS (possible- meaning the OS is bugging out, not the game) or the communication OS layer is sending info to the game (re: state, in case game code wants to re-align some of its UI? dunno) and the game is handling it erroneously meaning the devs fucked up. or there's a hardware issue that is completely contained to the unit where the crash was occurring (bad memory? who knows)
again. pre-release and not final units skew someones perspective especially for someone who doesn't know what exactly is causing the crash. Saying snap is crashing it means shit. No. Snap is likely what started the chain of events that eventually caused the game to crash, but isn't likely the cause. (just an exposure of another problem somewhere down the chain)
^this is all just hypothesizing and not to be taken as gospel