Well there's two things.
The first, and most likely to be fair, is that they keep a first team slot open for another potential signing- rumoured to be Konate.
The second point is that they did this with Vini, Rodrygo and Reinier (yeah, who da fook is he), and that meant the 100m got registered as an expense for the Real Madrid entity, but not a direct effect on FFP at that time. It was a company expense but not a LaLiga salary and transfer expense in those years.
We done something similar with Yusuf Demir, and funnily enough, LaLiga decided to change the rules then to stop it not counting against FFP.
So yeah, let's see how the latest LaLiga rules are setup. It seems this is more than likely to free up a first team squad spot. But knowing LaLiga and FloPe, there is some way he managed to manipulate it.
But in the end, spending 60m and then registering as a Castilla player is a bit of a joke. And doesn't give the aura of financial strength that Madrid have tended to try and exhibit.
