Not necessarily. Counsel for the player could easily argue its distinguishable from Bryant since the Bryant case still involved actual minor league games as opposed to just taxi squad practices. Actual games against a variety of different opponents and pitchers is much more specifically tailored for real, legitimate player development than not even playing actual games and doing just drills and BP against the same small set of guys, which wouldn't even involve scouting reports and the same type of film study and preparation as the real thing.
Thats why the Sox need to wait a "decent interval" after the point when the extra year was obtained to try and proactively defang an argument like this, so that they can make it look like the demotion wasn't just a pretext for service time (even though it plainly is). I also would expect, if it got to an actual arbitration, for the Sox to point out that the Sox were struggling at 2-4 and in need of a major upgrade at 2nd, particularly defensively, given Garcia's errors, and yet still kept Madrigal down for another 3 games which would actually translate to almost 10 games in a normal season. That could also be persuasive evidence of a legitimate desire for player development.