Looks like Musk might be cutting the data brokers out entirely. Normally social media companies and ad networks have to share their data with data brokers who then use this information to track you across the Internet and assign a (likely or certain) name, face, SSN, credit card number, IP address history, medical-related search engine history, grocery store club saver purchase history, news article view history, Amazon and eBay histories, Netflix and Youtube streaming view history, and so on to the data, which the data brokers then sell on and share back to the companies they got it from, thus protecting them when they say they only collect anonymous data.
Must might just decide to keep all the data and stop giving the users the placebo-lie treatment and saying they don't collect personally identifiable data. His data becomes more valuable and the users actually benefit from fewer entities having access to this data too. Apple has promoted this exact model to their users as privacy-enhancing, in fact.