[refulgentis]

I wonder if it's because it's the one API that gets a full firehose log of every single ask my browser makes for data

[Nullabillity]

The asynchronous API is still around and still gives you the firehose. Removing the synchronous API only locks out adblockers.

[livre]

It is possible that that's the explanation but stopping just one API only affects people/extensions willing to follow the rules (uBlock Origin for example) while the bad players will just change a few lines and begin using other APIs. The end result is people are less protected because they have crippled adblockers and data can still be exfiltrated, and worse than that, malicious ads can't be prevented from loading anymore.

[rasz]

Of course not. Google is leaving that one in place, they are specifically killing possibility of cancelling requests.