Not at all. I have already written about the Cheesegrater 1.0 which lived for three years housing a PPC and for seven years housing Intel Xeons. The notion that you can't just pop a Xeon out of the Cheesegater 2.0 and drop-in a Xeon is an obvious fact. However, it is a huge leap in logic to then say that this precludes retention of the Cheesegrater 2.0 as the case for an Apple Silicon-based Mac Pro.
The Cheesegrater 2.0 case is an aluminum billet that can be lifted completely off the internals. There is nothing to prevent Apple from designing new ASi internals for the aluminum billet that gives the Cheesegrater 2.0 its nickname.
I never said CGv2.0 couldn't be used as a vessel for a future Apple silicon Mac Pro...
Previous poster was saying Apple planned to drop an Apple silicon SoC into the existing Xeon mobo, just because it has a CPU socket, which we all know is wrong...
All CGv2.0 needs to become an Apple silicon Mac Pro is a new mobo; the PSU & the entire remains of the chassis is still useful...