I had forgotten about this so evidently it has stopped, that said I have only ever used ublock origin and it was happening to me, with that on Firefox so I don't know about this theory that it's just that one particular adblocker.
I find it hard to let go of the idea that Google was doing this, but then again I suppose the fact that it isn't now would suggest they weren't behind it in the first place since the supposed motive for it was to push people to Chrome and if you just stopped doing this after like a month tops then it wouldn't be a particularly effective strategy.