I downloaded the details about the new instructions from the link at the ARM community blog on Arm A-Profile Architecture Developments 2022, they've now included most of them. WIth the new instructions they have increased the size of their ISA by 25%. This is just a description of the instructions, not any rationale or suchlike unfortunately and doesn't include the guarded calls. I think it is mainly the SME2 additions duplicating SVE functionality. It will take quite some reading to figure out what it is all in aid of, if they continue at this rate every year it'll triple in size every five years! ;-)