Is it possible to migrate a ‘non account’ Minecraft edition from Amazon Fire Tablet to a...

Yes, that's correct.
Despite fire tablets runs a custom Android version, Minecraft couldn't be downloaded on regular Android devices due to Minecraft was purchased on the Amazon Appstore, which is exclusive of Fire tablets.

They shouldn't since all the saved data is stored through the cloud!

I have cleared the caches on both devices and updated to newest version of Minecraft but they still won't allow me to sign in as a different user 😤.

If I uninstall and reinstall will they lose all their worlds etc do you know please?

Thanks 😊

If you haven't already, I would highly recommend trying to clear the app's cache!

If the “Fire OS” operating system doesn't allow that, you can try reinstalling the app, as this might correct the issue!

Thanks Josef. I'm using the same Microsoft account on both tablets. However, on the original tablet, Minecraft was downloaded from the Amazon store. On the new one, it was downloaded from the Google play store.

Thanks,

Scott