So when you say "try", it's not like he was leetcoding on the side or anything. The way roles work at this level is a combination of network, exec recruiters, and eventually you talk comp. I hate to stereotype, but I'm going to assume in this case that there is someone senior at Meta that he is strongly connected to who referred him in. And by "referred him in" I don't mean submitted his name to some recruiter, I mean informing him the role even existed and making sure he was on the short list of consideration. Often this person is even the hiring manager, these are not roles you just let the recruiting pipeline fill with any person who fits the screening profile.
replyBy "try", I mean there's a difference between applying and getting accepted, and getting an offer out of the blue. They've sent out some unsolicited offers before, and poached some executives that way, so that's why I ask.
replyYou're right though that the process in practice can be more fuzzy (e.g., you weren't looking, but heard of an attractive opportunity and then applied that way).