But then he made a number of unexpected career decisions. He didn't come from any of the ACB teams' youth programs, but rather from an obscure high school in the Canary Islands (they do produce a lot of good players over there). He rejected offers from several top ACB teams, including the ones based in the islands, in order to stay in school. In itself not a strange decision, but for someone who projected so high at the time it was quite surprising.
Then, when he finished high school and everyone expected him to join FC Barcelona (he played for them in a Euroleague-sponsored youth tournament) he turned down a contract offer and decided to go to college in the USA, ostensibly more for educational purposes than as a result of a basketball decision. This was seen as a very puzzling decision since a pro contract offer at that level would set him up economically and wouldn't prevent him (on the contrary) to get an education later on if his basketball career didn't pan out. In a recent interview he explained he was recruited by Loyola's assistant coach, who sold him the program's ability to get him a real education while still playing at a high level (I guess compared to other college programs where "education" is not exactly a priority).
He had been dragging a patellar tendonitis for some time and it flared up ahead of his rookie season, so he and Loyola decided he should have surgery to correct it, with the effect of losing most of the season, first recovering from surgery and then due to the COVID shutdown. He could not return to Spain for months due to the travel lockdown, and when he did he refused again to play with ACB teams since a pro contract would keep him from returning to Loyola. He did practice with an ACB team though.
He went back for his sophomore season where he put serious numbers against not exactly elite competition, so it's hard to gauge his current level. Because he was in the US and limited by travel restrictions he's been disconnected from the Spanish national team program, so he kind of fell out of the map from this side of the pond. In the meantime Garuba exploded in Real Madrid's youth teams and eventually in the ACB/Euroleague so he eclipsed Aldama as the top prospect of his generation. At the same time he kept dropping in the mocks from being a potential lottery pick down to the 2nd round and maybe even being undrafted. Hard to say how realistic those predictions were since mocks in the 2nd round are a crapshoot. But it was still a bit shocking to see him taken in the 1st round.
I have no idea if he plans to join the NBA next season or not. I'm not sure if he could go back to college. I find it unlikely he'd go to Europe since he's not going to get a better contract than his rookie scale contract, plus it'd be hard to negotiate an NBA out clause. Assuming he stays with the team my guess is he will be available for summer league and training camp and will spend significant time in the G league in his first season.
If he had fallen to the 2nd round the situation would be more complicated. He could get a better contract in Europe for sure, so he would likely become a draft and stash pick. The problem there is although a 2nd rounder is not limited by the rookie scale and could get an enticing offer if he grew up as a player there's the risk of him becoming a star in Europe and deciding to pass on the NBA (like Sergi Llull did, for example). No idea if this was a factor in the decision of trading up to #30 in order to pick him.
What do I think about the pick? I honestly don't know. If he gets anywhere close to his projections from high school this would be an incredible pick, again, he was unironically compared to Pau. But he also looks very understrengthed for the NBA, I could see him being pushed around like a ragdoll until he puts some muscle on. I could also see him flaming out if he doesn't show progress quickly. On the other hand this is a player that has proven he's not attracted by the big city lights at all. If he turns out to be a good player he could be a lifer.
We'll see, I'm as surprised as you. I'm moderately optimistic but he's not going to be a contributor out of the gates.