Ello =) Firstly, I want to make it very clear that anyone can play whichever game they wish. If you are a FeralHeart player, but also wish to play FU/FNFH, then you are more than welcome and have all the right to do so. Players who want to play both, or solely just FU/FNFH over FeralHeart are not considered to be disloyal, nor are they marked to be banned off of FeralHeart. Making your community pick a side is highly wrong and immature. Everyone should feel free to play whatever game they wish regardless of what anyone else says.
If you wish to leave FeralHeart, then that is entirely your choice and nobody else's to make. It is always our hope that players would stick around, but we cannot make them choose, nor should we ever try to.