I suppose if everyone is fleeing the service, less infrastructure is required.
Why would everyone flee? Twitter had a problem with censorship and Musk is going to fix it. Some will come back, some will leave, the tone overall will change a bit, but that's about it.
A substantial share of the userbase either disagrees with Musk that there was a problem with content moderation or has a view of the nature of the problem that is at odds with Musk’s.
The other thing Musk seems to be surprised to discover is that the while tweaks might be desirable, the basic outline of content moderation and advertisers confidence in it was very much tied into Twitter’s ability to make money, and since he’s saddled it with a very large amount of additional debt service costs, that is something that becomes quite an acute problem if it is lost.