I think it makes sense to start doing thisNot so sure that's the main reason. The new cap won't apply to U21 players, which all the ones the club has recently sold are, so they could still be loaned.
It looks more like the club have changed their strategy and are going for a straight sale with a buy-back rather than a loan. The benefits have already been highlighted by a few, seems to be a good shift.
The sell on amd buy back covers us amd we can then watch the players develop like Douglas luiz and angelino
These rules are being designed to stop us and Chelsea but long term it will strengthen us financially