Statements like “Please get approval at least a month before you move” always rub me entirely the wrong way.

If I’m working remote it’s because I don’t want to be bound to a certain location, and whether or not I move is none of the companies’s business as long as I fulfill my duties.

Although GitLab is especially egregious in that it pays different rates based on location, I'm not sure that it's practical from a legal perspective to say where you live is none of the companies business. If you're an employee (as opposed to a contractor), the company has certain legal obligations that may change depending on what state or country you call home.

Or... if you're working remote it's because you like the peace and quiet of working in a private space ... and enjoy not having a 2 hour commute a day. There are more than one reason to do anything.

Now I'm sure if you were interviewing at GitLab, you'd know about this policy in advance (because it's public) and could plan accordingly. Or ...hey... ask your manager to be if they'd have any problem with you being a digital nomad on the job. The policy basically says you only need approval... so you could ask.