I'll call it:
Saylor doing a private OTC buy.
Maybe we see this in an upcoming Microstrategy press release..
There is plenty of supply available in the OTC market, there is no need to activate a 14 year old address for this. Really why do people keep coming up with random theories that make no sense. For this case I've seen everything from Roger Ver to hacks and now even Saylor.
There is a strong possibility that this person totally forgot about this humongous stash all this time and probably never bothered checking crypto news at any point until recently effectively waking up his/her dormant memory regarding it.
That would be the best case scenario for this person since it's far easier HODLING something when you don't even remember it in the first place.
I don't think he forgot, but he did it on purpose, saving it for quite a long time, he is a true Bitcoin Holder, or maybe he is active so far in the web3 world, we will never know about it, his bitcoin is his old age savings, and yesterday he only updated his wallet.
The stories about forgetting are very often exaggerations anyway. If someone didn't forget their coin, then there is no news story at all. That's why they make that shit up.
Just relax poor man and take a deep breath, you need it. That post is off topic, don't break the rules.