Static Web App moved to another subscription is still billed to the original subscription. What happens when the original subscription is cancelled?

We moved several Azure Static Web Apps (Standard plan) from subscription A to subscription B in the same tenant, using the standard resource move. Subscription A is a CSP subscription, subscription B is under an Enterprise Agreement.

The moves succeeded. The apps show under subscription B in the portal and in Resource Graph, and the original resource group no longer exists in subscription A.

However, months later Cost Management still shows the Static Web Apps charges on subscription A every day, with resource IDs under subscription A's path. Every other resource type moved from the same resource group bills to subscription B. A Static Web App created directly in subscription B bills to subscription B.

Questions:

1. Is it expected that a moved Static Web App keeps billing to the subscription it was originally created in? Is this documented anywhere?
2. If we cancel subscription A, what happens to these Static Web Apps? Do they keep serving, get disabled, or get deleted?
3. Is there a supported way to move the billing to subscription B without recreating the apps? Recreating them would change their default azurestaticapps.net hostnames.

We checked the move support and move limitation pages and found nothing about Static Web App billing after a move.