The real question is wich product do you use actually. Not all product are yet compatible. some are awaiting a new management extension.
I tested the 5.9 ePO server since the first beta and, even if i'm now stll in 5.3.2 in production environment, it's just because i was awaiting one extension upgrade to let met migrate to it. In my case it was DXL. As the 3.1.0
is now available since a few days, i'll prepare this migration.
here is the link to the ePolicy Orchestrator 5.9 supported products
My apologies for my english level.