With all due respect, you have no idea what you are talking about. Saylor has repeated ad nauseam that he will never sell his bitcoin, referring to MSTR, other than that he also personally holds them and will not sell them. But it is not only that, he has based the value of his company on never selling and never stop accumulating, so if he were to sell (leaving aside a small sale at the end of the year for tax purposes, as you mention) it would automatically mean a drastic drop in the share, and he is not going to stick a thread in his foot.
At the moment the plan is to get $42B the next 3 years to keep buying more bitcoin.
I see what you are saying and you are correct. Michael Saylor has made it clear that he will not sell his Bitcoin both personally and through his company MicroStrategy. His plan is to keep buying and holding Bitcoin and this approach is key to his company value. Saylor past actions and public statements show he is serious about this. If he changes his plan it could harm his company stock. He plans to invest $42 billion in Bitcoin over next three years which shows his commitment. Your observation highlights how important it is for Saylor to stick to his long term Bitcoin strategy both for his company success and his own investments.