I may be involved too much to see the ambiguity here 
If an eLicenser (USB-eLicenser and Soft-eLicenser) is registered and contains a license we offer updates/upgrades for, those can be made even after the servers are shut down. We have found a reliable way to bypass the server check for eligibility and rely on the registrations made in MySteinberg.
Of course, you could register a spare USB-eLicenser but if that eLicenser does not hold any licenses, there is no use for it.
Anything that requires a license transaction within the eLicenser system does not work anymore after May 20, 2025:
- move licenses from one eLicenser to another
- reactivate Soft-eLicenser licenses
- Steinberg Zero Downtime