If I have a watch only address in my wallet and then I import the private key corresponding to it, will I need to do a rescan or will it automatically update my available balance with any UTXOs for that address (at least those created since I began watching it)? It seems to me like it shouldn't require a rescan but I'm wondering if anyone has actually done this successfully.

If I don't get an answer here after a while I can test it out myself and report back.