Yes, though there is a protocol they are supposed to have gone through before this? ie they are supposed to have called you in, discussed attendance, set a minimum attendance thereafter, put the YP on a ‘warning’, clarified that the consequences of not meeting the criteria of the action plan would result in exclusion etc.
Did any of that happen? If not, then I think you have grounds to go back and appeal - but if YP is now so far behind, it might be better for them to consider redoing y12 (you have until 19 in free state ed, so restarting y12 in what would have been y13 is really common, but there would have to be an undertaking by yourselves and YP to address the behaviours etc). A move to a different college may be a better move and offer a fresh start, so also worth considering.