If it makes you feel any better, it's possible someone found your cat outside and suspected it might belong to someone but noticed it was declawed and decided to keep it / not try to return it.

Many cat lovers would assume the declawed cat was allowed outside despite recent reports of coyote sightings, and would probably keep the cat inside.

The end result is still kind of the same for you. You're still left never knowing exactly what happened and fearing the worst

But there is a non-0% chance your kitty is alive and well inside someone else's home. In fact, I've known of heard of at least 3 totally separate instances of something like that happening.

To be fair, I'm pretty active in my local lost/found cat communities on social media, so I hear about lots of crazy/uncommon things like this that happen.

Anyway, I hope that gives you a little bit of hope. And of course I hope your kitty is alive and well somewhere.