They meant cheat in the aspect of basically throwing the game in one way or another. Not necessarily actual cheating or using third party programs to cheat with and only in ranked matches. You can still play custom with your friends in party.
Not being able to match up with party members will basically help thwart playing games that either the outcome is already decided before the game starts, or the outcome of the game is something that is rather not intended by development such as both hunters and monsters not attacking one another and literally making the game drag on till the timer runs out, or you solo queing and being up in a game where the rest of the players are in a party and let the monster win etc.
I’m rather interested to hear what anti-cheating software they will use, if any. But then again some people don’t typically announce what they intend on using so people can’t get the jump on things to try and work around it.
The game is still under development and has yet to be publicly released, I doubt we will hear nor need to worry about such things until closer to launch when there is a large competitive base