Which, on the other hand, caused a huge mess some people are still cleaning up, since it added lots of duplicates and meh-ly entered data. So: possible, yes, done properly before, no. There's also the FreeDB bot that added tons of releases ages ago, but was stopped because data was also terrible. All this has made the community not too receptive to bot-adding.
That said, a properly written bot, with sources that are reliable and run in a decent way (tested, with a small test run checked carefully by humans afterwards to find any issues), for music that is unlikely to get added otherwise, and with some good way to check for duplicates and not add stuff to the wrong artist because it has the same name, would be useful and I would definitely lobby for it with any community members who don't like the idea. The problem is that it's not easy