I understand from distance what happened with Juan looks as you described. What I can tell you is that his knee injury from the crash on the strade Bianche stage was much more significant than was generally known. Juan is super nice kid, very motivated and with a lot of pressure on him in Spain, remember in Spain every kid who does anything is pushed as the next Indurain or Contador. He is a better team player than he is portrayed, but definitely has his own ambition as he should. As too your comment re Isaac and UAE would rather have him than complete against him. I would argue UAE are very good at developing talent once identified. Look at the L'Avinir winner from the last 10years and which ones are in a position to win a grand tour. Obviously success breeds success.
Look what Tim is doing now. The tour team is known at the December training camp. ( No changes were made to the team from December) compare that to Ineos where guys were at the pretour training camp 10 days before the start of the tour and didn't know if they were riding.
Watch for Pablo Torres, you won't have seen much from him this year - he had a big crash in Hungary, but he is going to the the next superstar pure climber.
Ah and Vuelta is Tadej and João co leading. No Isaac or Juan. Max 1 grand tour per year for the u23 riders at UAE.