Higbee is a very good blocker, even able to block some OLBs and DEs 1 on 1.
Further, he has above average speed, is athletic and a darn good receiver.
No way they trade or cut Higbee. In fact, I think he'd be a guy that they might try to extend and gain some 2021 cap space.
I really don't think the Rams will mess with their WR corp or their #1 TE in order to get a deep threat.
I could actually see them signing someone like Hill on a cheap 1 year deal just so he can play for a winning team again and probably only have to play around 30% or so of the snaps.