This is very very bad suggestion. Obviously you were never the NT coach and donāt know the amount and time required for scouting and communication. And also the response rate/time of managers. If you also would need to put more time each Monday for tactics because some schmucks donāt want their player to be called (which has no downsides, only upsides, with increased merchandise and etc.), this would be unplayable.
We also have one case in NT, where player is taken as a hostage and his owner asks IRL money for him, with your suggestion there would be tens of those cases.
Being NT coach is not a full time or real job, if people do not have time to work for it they simply have to play as club manager. It's not my problem if someone is doing a job too big for him. If someone is not able to be NT coach because he has no time for it, well, just don't be NT coach. It's easy.
But I do not understand why to make this game more fun for someone (who has no time to be NT coach) it should be less fun for me.
PS
About the players asking money, lol, he'd be crazy, it's easy solved: well, just do not call in NT his player! It's not about humanity future, it's all about basketball internet game, losing a world cup or a qualification match because one manager do not want his player playing in "prestigious" NT, it's not a big issue for the world. It happens in RL, I do not see why it would be a tragedy in BB to lose a player for a NT.