Looking for advice: Why were my photos rejected on Adobe Stock?

Think about your composition, although from a drone shot, it can be a lot more difficult!

Composition:
https://www.adobe.com/creativecloud/photography/discover/photo-composition.html

This could be an example where the moderator struggled to give a good reason and ended up choosing whatever was quickest. 

Frankly, I'm not impressed with any of the shots, there's a lot of information on your shots and nothing stands out.

So I'm going to give you photographer/cinematographer advice:

Avoid shooting at noon, unless you are shooting straight dowm.  ALWAYS think of your shots ahead of time, scanning your sorroundings. Here shooting straight down would have given you amazing composition opportunities, as well as the best lighting conditions for the overhead sunlight.

The fron of the church in the plaza is lit by the sun... so prioritize shooting that facade, that would have also help with the blownout clouds issue. (which byt the way Adobe's library is filled with images with blown out clouds, so that alone did not cause the rejection in my opinion)

Always shoot raw, and always use discreet sharpening and grain reduction to your dron photos. That's what I do, I shoot with the mini 3, which is less quality than yours, and all my drone photos have been accepted. 

Again, I can not over emphasize Composition matters more than anything and that applies specifically with aerial shots.

Keep having fun and you will see your work get better!

Cheers

overexposed highlights in all three photos and possible IP violations (signs) in the first and third photos.

Then we are probably talking about burned out highlights and the rejection reason was incorrect.

There appear to be blownout areas in the clouds in the first and third images.

So they were photos and not videos? The moderator probably selected the wrong rejection reason. If they were in fact videos, post one here.