over 4 years ago - UbiMorning - Direct link
Hey there!
With the MMR Rollback system, if you lost against a cheater, you do get that MMR back. If you played with a cheater, you get that MMR removed.
The goal of the system is to remove any impacted matches a banned player was in to nullify the results they caused across the board.
It is also important to note this process is not instant. It may take a bit for the system to process all matches.
I suggest taking a look at this post[rainbow6.ubisoft.com] for more info on how the system works.