You're just making stuff up at this point with no evidence or source. If the intention was to forbid dynamic fetching of declarativeNetRequest filter lists, Google could also just... not have dynamic filter lists.
Google's playing the long EEE game. They do small things like this so people like you go around telling us it's not a big deal.
Will you say the same things 5 years from now? Google needs to be kicked out of consideration for web standards. They keep treating it like they own it.