I've taken that as a hint that eventually my team will cease to exist
in this location.
That seems pretty clear.
I want to move to another team with a future in this location so that
I have the motivation to learn and progress.
Am I right to move team?
Since the corporation feels comfortable replacing the high cost folks in your subteam with workers from a lower labor cost region, how confident can you feel that exactly the same fate doesn't await all other high cost folks in other subteams at your location?
If it were me, I'd be looking for a job at a different corporation. (In fact I have done that exact thing a few times over the course of my career, for exactly these reasons.)
How do I explain this to my leadership when/if they ask why I'm
You could "fudge" your answer by indicating how much you always wanted to join the new team.
Or you could be honest and convey your concerns about your existing team.
Make your decision based on your knowledge about how your particular leadership would react to your decision.