They will continue to optimize for performance, but if you expect a major breakthrough you might be disappointed. After all this is a game with fully dynamic environments, running on Unity game engine which is not exactly known for its efficiency. Valheim will never run as well as some other game which features mostly content that was known at the time when the game was made. You can optimize LODs, lightmaps, asset streaming etc so much better when the exact content in the game world is known in advance. Procedurally generated games such as Valheim do not have this luxury.