This blog post does not do a good job of communicating the status of these PEPs, for example the first one "PEP 671" is in Draft status and it has not been accepted by the Steering Council.

In fact I would be surprised if it did get accepted as many members of the Core Dev / Steering Council have similar reservations about extending Python's Syntax as others have expressed in comments here. As demonstrated by their recent rejection of PEP 677 (Callable Type Syntax).