I like the idea a lot, and if you want to really help NTs there is even a better idea/solution that this one that might complement each other greatly:
Put every Drafted player by a bot team on Transfer market automaticly once they arrive at those teams. This way any team in the world could buy them and give nice 2nd chances to some of the player, because even with what you propose, there will be some good players in bot teams.
If those players end up not being sold, they are extremely bad, so the bot team should get it forever, but for me, there is no point in bot teams to keep new players. Bot teams are meant to occupy a place just for the sake of the competition.