If you had multiple B.Net accounts, on a single authenticator prior to the change where an authenticator cannot be added to one account if it already attached to another...

When I was setting up my 10-box, I had Blizzard tech support spread my accounts to multiple B.Net accounts.
Originally had one B.Net (with a single Authenticator) protecting accounts: A/B/C/D/E
They moved them like this: A/B/C and D/E; I then added them like this: A/B/C/F/G and D/E/H/I/J.
All ten accounts were still protected by the single authenticator.

I'd imagine A/B/C/D/E are each linked to Authenticator 1.
Any number of accounts, in any configuration that is attached to any of these B.Net emails, is going to stay attached to the Authenticator 1.

However, in the future new B.Net accounts cannot be attached to this authenticator.
And if for whatever reason I remove the authenticator from an account, it won't let me re-add it if it's already attached to any other accounts.