No, he won't want to buy Bitcointalk, never.
Because bitcointalk is not a fancy platform to build connections and shill your posts to walls, notifications of other users who are in or not in your connection/ friend/ follower list.
It is different than social media platforms like Facebook or Twitter when your notifications will be spammed with many statuses and tweets from others.
Bitcointalk is not a place for Elon Musk to play with his jokes that he always loves to do.
I found the thread a joke. By now we should know what Elon goes asides the money and the fame is after his ego. Bitcointalk does give that size of fund for the world richest. How many people use and visit the forum like before, so no ego to fight for. By now Jack Dorsey won't be happy he sold that app to him, many people will leave twitter soon and a similar app will replace it. My worry is how crypto community will respond to it when many leave.