Not sure he has enough experience just yet but he has the physical tools. I don't care how old he is. If someone uses a mid-round pick on him and he ends up being a cheap player who plays very well for that team for 3-4 years then lets him go as he becomes more expensive, it's a nice win for the team that drafted him.
What I have read is that he is not a nuanced route runner yet, is not great at finding holes in zones yet and does not seem to be into blocking when the ball isn't in his hands. I just don't see him fitting the type of WR the rams prefer. But I don't think the Rams care if held an older rookie or not, either.