Generally, SRM 8.1 supports the same Windows host operating systems that vCenter Server 6.7 supports.
From the documentation section you mentioned - Site Recovery Manager System Requirements -> click on "Compatibility Matrices for Site Recovery Manager 8.1" -> Host Operating System Compatibility for Site Recovery Manager Server ( Compatibility Matrices for VMware Site Recovery Manager 8.1 ) -> VMware Knowledge Base
Hope this helps
That's what happens if you are searching for answers the whole day and doing tests for a concept (vSphere Replication doesn't seem to trigger pre-freeze scripts in SLES 11 if you quiesce the Filesystem, but manual snapshots do)....
I should have scrolled down and read more.