I trust Blizzard more than you to know how this affects bots. This change has zero negative affect on a large majority of the playerbase, and it certainly has at least some affect on bots. Bots negatively affect everyone, so any small change is good, while the instance cap only affects a small handful of players. If bots are outside dungeons that means they are easier to report. Just because the cap doesn’t have any directly visible improvements to gameplay doesn’t mean it’s not helping
They said they are still working on ways to combat bots, so they know this isn’t a good permanent solution, but changes aren’t going to happen in 1-2 weeks.
You can still do anything in the game that does not involve a dungeon or 20 man instance. Or you can change server and do more since apparently that is not inconvenient at all.