From what I've heard, Jenkins can play CF well enough and should certainly have more range than Roden (of whom the team hasn't trusted to play CF a single time in the majors this year) so it'd be more than just a better arm.
Y'know, I'm reminded of a past prospect of ours who was once called up from AAA after only hitting .660 OPS in his first 100 PAs there, some here thought the team was rushing him, but he ended up seizing a starting OF job and was a 2.5 WAR player his rookie year. That was Eddie Rosario.
Oh, and Luke Keaschall had a .710 OPS in his first 120 PAs at AAA before getting called up... and while these are two anecdotes and not proof of anything, Jenkins is definitely a better prospect than both of them.
And neither of the two I mentioned were hitting HRs, Rosario had only 12 HRs in over 600 PAs at AA before hitting just 3 at AAA... and by your strategy of being held at AAA for "a while", Rosario and Keaschall would never have helped the 2015 or 2025 teams. Keaschall may never hit for much power, but that might just be who he is - if that is what Jenkins is, why sit on him at AAA indefinitely (I interpret "a while" as several more months / indefinitely) rather than getting him acclimated at the MLB level and getting what you can from him?
I get this team not wanting to have Jenkins take his lumps while the team is [supposedly] in a pennant race and the whole other aspect of putting him on the 40 man roster early, but I don't find the strategy of "sit on your prospects indefinitely until they hit for power at AAA" to be convincing or productive for the team.