This is official answer from Nordeus:

“Be aware that at the moment only players which you purchase from the auction can have a Playstyle which is visible to you as well. Players from the Youth Academy do not have an active Playstyle even when they join your main team in the following season.

We aim to constantly improve the features in Top Eleven so that we can provide the best possible user experience to our managers. If there is any feedback or suggestions you would like to provide us with regarding our newly featured Playstyles or something else related to the game we will be more than happy to hear them.

I hope this information is helpful to you and if you have other questions or concerns do not hesitate to contact us again.“

So, this is end of youth academy.