He's kicking into x.ai. There are good reasons to think that he bought Twitter to use its massive data-set of human language to train an ai - NOT because he gave/gives a shit about Twitter as a profitable company.
If it becomes a paid competitor to OpenAI, it solves its profitability issues without enhancing "Twitter" as a social media site. Anything he said about improving Twitter was likely a lie designed to prolong usage of the platform and enhance the dataset.