That is probably 80% of teams. There would be not enough teams to play in the leagues.Plus a player has 3 seasons of contract so yes the game is obligated to respect that period before replacing them with free agents so that is fair enough.

If you want to play in an active league I suggest you send friend requests to a lot of teams in your level (find them in cup CL and league) this way there is a big chance you will end up in the same league with them.