You're probably right but I'm not entirely sold on the idea that this is just to get more signed up.
The first thing that springs to mind, is that if Elon is telling the truth, it seems the verified users thing did bugger all to stop bots which he said multiple times.
On top of that, let's pretend Elon is telling the truth and it's entirely due to bots. That means Elon has basically said "I'm going to do something that makes it worse for users, because we are too much of a failure of a company to stop bots. Those bots will worsen the experience for the end user, and our failing has caused this.
Bots aren't a problem for the end user. It's nothing to do with them, however Elon's so current solution is a problem for the users.