Earlier quoted context omitted.
I think that's a bit unnecessarily tin-foil-hat. If they didn't put in the 8 second css rule it would just show blank for those users right? So adding that rule is making it work at all instead which doesn't sound like "there to punish them".
It's the other way around -- AMP pages show a blank page for 8 seconds for people with ad-blockers because of that CSS rule.
Certainly an ad blocker can be used to block any URL, but I don't know of any that block this one by default. If there are any, let me know and I'm happy to file issues to get that fixed!
If a user chooses to block this particular resource which the page needs to load, then the page still loads after 8s.
Similarly, if the site owner chooses, they can run the AMP Toolbox optimizer (https://www.npmjs.com/package/@ampproject/toolbox-optimizer) which lays out the page server-side and removes this CSS flash for most documents. Some documents can't be laid out until the viewport size is known.