Hard to say, but If we go by the assumption that they stopped doing that, they either stopped before MD started enforcing that rule, or they recieved some kind of "ultimatum" and decided to stop doing it.
But that's only going by the assumption that they stopped. I don't really know of that's...
The scans group was banned for paywalling chapters.
After the mass DMCA strike MD got last year, the staff no longer permits MD to be used as a means to make money by paywalling "advanced chapters" for any reason.
MD already made an example out of Asmodeus Scans. And more groups are being...