I looked at the space and thought "this is an incredibly small venue".
NCL seems to be trying to address the venue size issues with the Prima+ ships. Improv moving to a larger square footage room across the hall (SNPH), SNPH moving to Deck 6 and gaining square footage by taking up a chunk of the aft section of the casino. Whiskey Bar swapping spots with Belvedere. They're all positive changes in my opinion.
As far as what the future use of the improv space is, I don't really care. It's super small, it isn't next to anything that they could expand into the space, so.... Sure, make it a shop. Close it off and use it for storage. Whatever makes sense.