This is honestly the most overblown issue I've ever seen on HN. How many people are buying a brand new in box pixel to install a custom OS on and do not have an internet connection anywhere, not even a free public wifi? I'd be shocked if this impacts even a single person.
At this point it's being angry for the sake of it.
I can totally imagine a situation in which, in the future, someone buys a new old stock pixel phone and can't replace the OS because the bootloader can't be unlocked because the servers don't exist anymore.
A few years ago I bought a Nokia N900 which was at the time a 10 year old phone. I did this to use it as a daily driver.
Without community support the phone would have been useless. But, more importantly, if the phone required an internet connection to some server in order to let you replace the stock OS then it would have been a brick because Nokia's servers were long gone by then.
That being said, all things considered, the most important argument here is not of the practicality but the principle.
You handed over money for a piece of hardware but you can't make full use of the hardware until you let the phone talk to the manufacturer once. Thats completely insane irrespective of how small of a perceived issue you think it is.
At this point it's being angry for the sake of it.