They were not "blocking" ads and trackers, those features are not exposed by the API. They couldn't do it even if they wanted to, which was discussed at some point.

>Hell you can't even browse Reddit without an account anymore!

Yes, you can, via old.reddit.com.

Not sure what you mean by "trackers". Reddit knows exactly what you did in the 3rd party app via the API. The app tells the API who you are.