If you're using an adblocker, you probably also don't have any positively identifying google cookies, which has become more and more synonymous with "bot" to them. They could defend it from the opposite direction: when you're logged in to google they trust they know you, so when you're not, there's a lack of trust. Not suspicion, no, but a factual lack of trust. There's plausible deniability if anyone ever claimed it's suspicion, and that they do it to punish people who want to remain independent and anonymous. But if that's the effect and they don't do anything to prevent it...

To me it feels similar to the duality of gas station "cash discounts," which have also been perceived as "credit card penalties." Or mobile providers' "free data for the music streaming service of our choice."