If Larian is looking into solutions on how to reduce rest spamming, I hope they consider just having certain areas where you cannot do long rests (e.g. Spider caves). This already exists in the hag's lair, so I think it's likely they're planning it for other areas too.
Just disabling resting in certain locations doesn't solve the problem. You're not locked inside the hag's lair, you can leave at any time and rest right on the doorstep. The map's not that big either, so it doesn't even take long to run outside. It may dissuade some players from backtracking on bigger maps, but not the determined ones. You can't lock the player inside either, because that can lead to an unsolvable game state if you're, for example, too low level to deal with the hag.
Random encounters strike me as a way to cheese the game: spam rests and farm experience and loot via random encounters. Remove all rewards? That would feel artificial in its own way. But a static world is a problem as well, so I honestly don't know.
Right now you're actually encouraged to spam long rests, and that's a big problem. By playing efficiently and resting as little as possible, you're skipping a huge part of companion interactions. You have to rest
three times between landing on the beach and getting to the grove if you want to get the most camp scenes, it's ridiculous. So in light of that, are Larian even interested in preventing rest spam? They seem to have integrated it into their design.