Forefront Identity Manager (FIM) 2010 R2 is removed as a product from the April 2015 Product Use Rights document (see page 5) and the right to install FIM is moved to Windows Server 2012 R2. New text on page 39 of the April 2015 Product List states that customers are allowed to run an instance of FIM for each licensed instance of Windows Server that they have.
Licences for users to access FIM functionality are still required and pages 25/26 of the PUR tell us that a FIM 2010 R2 User CAL is eligible, as is an Enterprise Mobility Suite User SL or a Microsoft Azure Active Directory Premium User SL or, for external users, a FIM 2010 R2 External Connector licence. Pages 26/27 state, however, that if a user is only using the FIM synchronisation service then a CAL is not required.
And what about customers who have active SA on FIM 2010 R2? Well, as long as it was active on 1 April 2015 then they’re deemed to have 1 Windows Server Datacenter licence, and you’ll find confirmation of that on page 39 of the Product List.