OK, but this is just an USCIS guidance to how they are going to interpret the proclamation when approving petitions. Important thing would be to have similar thing from CBP on how they are going to treat H-1B individuals at border crossings.

Yes, I know this memo above says "The proclamation does not impact the ability of any current visa holder to travel to or from the United States", but that means nothing, because it is coming from USCIS which has no authority here (CBP has).

Ah I didn’t consider that, great point.