The internet is not a thing you connect to, what you must actually do is register your intent to disable the bootloader with an adversarially controlled server, and that server must respond with a yes.
If the root comment is to be believed, this (connecting via the internet to Google's servers), is required to provide additional security. I'm just taking that as true and deciding that connecting to the provider of my phone's hardware and software _once_ as a purchaser of their hardware, is fine for me. I also imagine it's not too burdensome for others.
Scenarios in which that's not possible are hypothetical (disaster, totalitarian takeover, alien invasion, sudden policy change), and I'm fine calculating that into the risk calculus and deciding that, yep I don't mind driving home and unlocking it the same day I bought it and praying nothing changes in their policy during the drive.
That's basically what I did. We can disagree on this, but it has worked out OK so far.
