People can absolutely check me if I'm wrong on this...but this sounds a bit like Jackie Bradley Jr ten years ago with notably worse plate discipline but more useable speed and pop
2013 Jackie Bradley Jr - .265-.374-.469, 41-75 BB/K, 10 HR - 23 y/o at AAA, + defender, mid-20s to mid-30s in mid 2013 prospect rankings,
2023 Ceddane Rafaela - .303-.345-.520, 21-88 BB/K, 17 HR - 22 Y/O at AA and AAA, + defender, widely variable prospect ratings but generally lower half of the top-100
To your point is that JBJ's offensive value rapidly turned into depending on his plate discipline (which settled into a K heavy guy who could still walk) and the emergence of power. So even as he hit like .230, he walked often enough and had enough good contact that the offensive value was enough to justify playing his glove. That 21/88 split in a great year for Ceddanne is legitimate reason for concern as pitching is going to get a lot better really soon, and Ceddanne is going to be hindered if he's unable to put the ball in play at a decent clip. With that said, you're both also right that if he can give similar value to JBJ, which was a 2 WARish player floor with upside in a good offensive year, he's a player worth having and hoping for. But that line does exist and if he is constantly whiffing at the big level, it may not matter how fast or good on defense he is.
I think of another player who Ceddanne can definitely out-power but also had a ton of hype and has kind of settled into what I'd consider a different kind of cautionary tale
2013 (22 y/o at AAA) - .256-.308-.343, 38-102 BB/K, 6 HR, 75 SB , - 22 Y/O at AAA - + defender, prospect rankings were around #20 going into the year and around low-40s leaving the year
In the ML, he was a regular for most of his rookie contract deriving nearly all his value from his speed on the basepaths and defense in CF, but with an OBP around .300 and no supporting pop, and an average around .240ish. This guy was even faster but his inability to consistently make it on base really hindered the overall value which capped at an average if oddly average CF.
Overall, I think there's legit reason to be concerned. The 20% K rate isn't terrible, but walking that little combined with that worries me a ton and the weak contact discussion seems to align with that. With that said, I do think that lists that are excluding him are doing a disservice. Unless he is a true AAAA guy and legitimately can't hit MLB pitching, he will be in the majors and will provide some value. One more fun comparison to bring this full circle
2014 (21 y/o at AAA) - .260-.323-.510, 34-130 BB/K, 23 HR, + defender in the infield, Top 10 prospect going into 2014 and was called up md-year. At his peak he was an all-star caliber, 6 WAR type guy, but he was hugely variable generally with that 2 WAR type floor mostly hindered by a terrible BB/K Rate. Well...if the Sox get OF Javy Baez I think they're pretty happy.
Now I'm sure there's a slew of guys in the minors with this profile who bust and all of these are different people, but I think it's illustrative both to temper expectations and understand the type of player he may be...but also to push a bit back on Top 100s that have him missing. It does explain though why different lists have widely variable opinions.