Honestly it's no surprise that they got banned. Going off of their previous year, Ameri and the student council intervenes if they see any upperclassmen trying to force first years into joining; and Iruma's group (while Iruma and his friends weren't willingly) were doing exactly that on a much grand scale. That said, even if they're banned from the hunt and/or actively recruiting, I imagine that they're very much allowed to welcome any first years who wish to join of their own volition.