It is not clear if reddit has already engaged in this with Google, or if it is something that’s only starting. However, as outlined in my post, they might have to consult with a DPA before engaging in this anyway, which I doubt they have done. So, no, DPAs are absolutely the right place to make that complaint.
Even if they hadn’t started yet, might as well get their eyes on it, and force them to do it right from the get go (which they cannot do, as it currently stands).
Especially US companies usually just do things and are willing to engage in lenghty legal battles after the fact.they are very, very litigous.
Another issue to consider is that the GPDR is held vague on purpose since it applies to your neighborhood yoga studio as well as Google or reddit. Entirely different use cases. So there is a lot of room for interpretation.
Looking at the conduct just within Europe, yes, I think it is possible GDPR considerations were either ignored or downplayed to the point of irrelevance. There was a recent study by noyb.eu which showed that DPOs are still often pressured to make recommendations that do not align with GDPR principles.
Either way, the DPAs will have to decide if the complaint has merit. Given new technologies are specifically mentioned im the GDPR, I am at least very curious to see how it turns out.