Can you please elaborate on this? How can it be avoided?
It's there to say "no individual can legally own more than 15% of Twitter" as someone is starting to buy Twitter up. Not say "we're going to explicitly screw Elon Musk after he bought 25% of Twitter."
I'm guessing not: 1) if it were that easy to circumvent, it would be a pointless tactic that wouldn't be bothered with; and 2) I haven't read the actual language, but IIRC some articles that have described it as also including "family members and individuals acting in concert."
A good rule of thumb is: if it took you a short amount of time to think of a "cleaver trick" to defeat something "important," your trick most likely doesn't work. That's either because it fails for reasons you haven't through of or someone already thought of it and countered it.
See the definition of "Acquiring Person" in the rights agreement; it's the first definition in the document.
For that matter, if Elon promised Bezos, Gates and Brin they would make money on the deal (as opposed to doing it because it would be fun) it would also not be something they could do. Promise is doing a lot of work there.