Elon will never spend a penny on stock buyback just like marketing. Why? He'll always prioritize spending on physics first principles, like engineering headcount. It simply does NOT matter as it is at its best an indirect positive to the mission.Share buyback is the best way of transferring hard earned cash from the company to short term speculators or worse shorts. Longs will not be the beneficiaries.
On the positive side though, I am guessing it reduces the free float and hence decreases volatility.. maybe. I am sure others can correct me on that.
IMO, talking about this is moot for Tesla or any Elon run company. Other CEOs are materially different...