Just going by the eyeball test, he's definitely got length, and he appears to be physically immature, which is what you'd normally expect from a high school kid who is 6-10 and not getting Valentine's Day cards from Calipari.
You're right, it's difficult to gage what he brings based on the competition on the video, but watching Poeltl dismantle the freshman Chimezie Metu last year, I'll take upside, some maturation time and hard work from a kid with that kind of undeveloped potential. This kid reminds me of Metu, from 2015-2016. (I wonder what Metu's HS video looked like.)