I believe the subscriptions are tied to the app id which has nothing to do with the DevID. I just did a test with one of my private channels I used for testing subscriptions and I could upload a new package with a different DevID and the subscription stayed in place.
-JT
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee.