Honest feedback is that he's is nowhere near a 1.88. The best MLB catchers barely avg that. Legit awesome throws in the show are 1.8-ish. Definitely some below. Sanchez the other night was 1.83 from his knees.
If I see arc in the Cs throw like your son's, it's not very likely its sub-2.0. The throws on the video I got at 2.10 and 2.19 on my stopwatch, and those aren't live game reps trying to get a strike. While I'm not saying he couldn't possibly throw 1.88 in a very controlled environment, it's nowhere close to a realistic representation to a college coach for recruiting purposes and probably hurts more than it helps to list it that way. A HS catcher consistently around 2.0 will shut down a lot of running games. Sub-2.0 and only the elite guys will even try to run.
Do you have a velo on him you could post? That would help. If he's close to or over 90mph than 1.88 is more likely, it just doesn't appear that way in the video.
I hope this doesn't come off as harsh, as I don't mean it that way, just unbiased feedback from my perspective.