Many types of A/B tests are designed to increase conversion - to get a user to buy something, or signup, etc. I have personally (and I'm sure lots of folks on this site) been involved in A/B tests that specifically test what many would consider "dark patterns" to increase conversion.
Just take a look at Booking.com, which is famous for their A/B testing. Right now I get a popup banner when I hit that which says "Welcome back! It's always a pleasure to see you! Sign in to see deals of up to 50% off." I guarantee the text in that banner has been A/B tested 9 ways to Sunday. I'd even bet they tested the percentage amount (i.e. whether it was 50%, 30% etc.) Of course "up to 50%" could mean 0%, which it probably is in most cases. And the whole purpose of that banner is to get you to authenticate and sign in, so they can track you better.
So yes, it most definitely will apply to certain forms of A/B testing. That also appears to be the point.