Given that, at least through Steam, games and characters can be saved to Steam Cloud, a "wipe" isn't going to happen in the sense that I would normally think of it. If it really becomes required to "wipe", we'll all simply get messages that say "you saved game/character is invalid.
I don't think Larian is storing anything on their servers. They might have a "match" server, which shows who has a public game server running that you might want to join, but I really don't see a wipe coming.
