I do not exactly read this memo as saying you can’t use “Palestine”. Image from the article:

Like it says you should use “Palestinian” in some cases. How can “Palestinian” exist without “Palestine”?

There are some other wild things in this note such as “Canada and many other Western Nations”. Like who is deploying capital letters that way in 2023?

The vibe comes through loud and clear though; I believe the overall claims about the atmosphere.