Username Change

Hello. I understand that the previous danbooru name will not show up on search engines except for logged-in users, but will the new, changed name will? Also how long would it take for search engines to index previous posts made when changing the username, if it will?

The new name will show up in search engines.

No idea how long it takes to index previous posts after the name change. That’s up to the search engine. It could be anything between a day and a year, if ever.