This would end day-trading immediately.
But there is no will and no need to stop day-trading. This change makes it only less profitable. Fair enough.
There were steps undertaken to make rosters more stable:
- reducing GS after transfer,
- less tickets sold when you attempt to sell half of your team permanently,
- giving bonus to trainees in overspending luxury-tax,
- now it is tax risen when selling new players.
All the changes made moved the game in good direction (I believe).
Would you be willing to be forced to keep a player for one year just after having to buy him because of 4-week injuries to both your starting bigs? Now it's the way - you can do it, but you have to pay for it and calculate.