Sophos Mobile Migration with expired license

Hello Community,

so here's the situation:

Our customer has a Sophos Mobile Control Standard server on-premise and wants us, a MSP, to migrate the Mobile Control to Sophos Central. 
Currently they have Sophos Mobile Control Server version 9.5 installed and the license expired in May 2021.
We know that we need to update the server to the newest version to be able to migrate. And we'll need the matching Sophos Central licenses beforehand.

But here's my question:
Can we migrate to Sophos Central without renewing the Sophos Mobile Standard license of the server?
Or do we need to renew the server license for a year just to migrate the devices?

Thank you in advance.

Greetings,

Florian