Loan period is one season and if someone loan out player just for last period before selling him then he probably can't sell him on short TW. It will also mess up calculation of games to guarantee needed number of games.
There is noone who would make any changes in game- that should be known fact for manager of 20+ clubs.
What will do with loans manager whose system is next?:
1) sell all promising and younger players
2) spend all money for last breath oldies who will boost team for some 2 seasons and then will die letting club without money and any sellable player
3) jump to another team