While I don't particularly mind if we get ExceptionGroup, giving
it special magical semantics, and especially new syntax, seems like
bringing a massively overpowered weapon to bear on something that
will only be used rarely.
Handling multiple exceptions from an ExceptionGroup could be done
using a loop with pattern matching, so is except* really justified?
It is of course an option to split the PEP into two, add ExceptionGroup first and then ask ourselves if we want except*.
We do have some experience with this from the Trio experiments with MultiError though, so we are not starting from scratch.
Can you spell out how you see ExceptionGroup handling work with pattern matching?