Well, I don't see how this would impact Google at all. Obviously as one of the biggest advertisers all of Google's advertising will fit within the limit and will be highly prioritized over others.
Yea, I would be okay with spending all 30k of those on just YouTube ads, and pihole for the rest. Google is the biggest advertiser, so logically their ads would go first or close to the top
If anything Google would be incentivized to increase the size, since that would impact competitors. So I'm just curious to learn more about the justifications - like I said, they've made a number of changes to the APIs already in the last two years or so.