Well, the man clearly wants to kill the thing so crossing it out is not anything unusual.
That Musk want to build a "X" ecosystem, something like WeChat. I hope the privacy watchdog will do its work to avoid to have a close ecosystem like in China, at least here in EU.
I hope they get all trademark appropriation lawsuits they deserve.
Rebranding and repositioning Twitter might be a "good" plan, but more effort at choosing a name would have been necessary.