We don't (and won't) know the full motivation here. There is certainly a monetization aspect of it, Elon even stated that clearly. There is probably an aspect of it that wants to get rid of all the anonymous accounts. There is an aspect of getting away from the data broker sort of business and ad revenue. There are plenty of motivations that we likely don't know. Lots of things play a role. Drilling it down to one specific thing and saying it is only that... certainly not correct.
On the misinformation tool and the firing of the executives... you're making a tie to this that may or may not have ties to this. To make that jump with absolute certainty at this juncture is early. The firing of executives, well, Elon was always going to clean house here. He hasn't exactly made it a secret that he's disagreed with their leadership (neither has his buddy Jack). On the misinformation tools... follow the guy heading it up, Yoel Roth. He's pretty transparent about what is going on (and he is no Trump fan). In any major change, you tighten things up to those that are staying and key personnel, then you open it back up as you have staffing in place. You don't let those being let go (or maybe let go) have any control of the tool for potential misuse. This is a risk mitigation tool that is very common (used it myself many times with personnel transitions)... it just so happens trolls have been exploiting the change (and people are increasingly ready to jump on any bad news here).