I hadn't considered or even been aware of this selection effect. One of those things I didn't know I didn't know.

Just looking at the raw numbers though, almost 6000 extra-solar planets discovered (with thousands more awaiting confirmation), that large of a sample size alone would seem to statistically confirm the hypothesis of super-Earths and mini-Neptunes being the most common planet types in the galaxy.

But beyond that, the Kepler survey data shows that around 30% of Sun-like stars have super-Earths, but the rate is much higher around M stars (Red dwarfs) - which are the most common stars in the Universe.