Do you know when the Freelance 2016 SP1 version compatible with Windows Server 2016
Freelance 2016 SP1 isn't and won't be compatible with Windows Serwer 2016.
Compatible versions of Windows are conected with version of Freelance, so maybe with new version of software another operating system will be tested. Of course no one (maybe except R&D crew) can say that for sure.
I can only add that new Freelance version is said to be released by the end of this year, although I did not get any info on compatible OS versions with this new Freelance.