Zen, edir 8.8 and migration questions

We have Zen 6.5 on 5 Clustered netware 6.5 sp7 nodes running edir
8.7.3.x. What I would like to do is remove one of the nodes and install
OES 2 linux on that node to start our netware to linux migration. Once
OES 2 is installed on the 5th node I would like to join it to the
netware edir/cluster. According to docs, 8.8.x is installed as part of the
oes 2. I have read that Zen 6.5 does not play nice with edir 8.8. Does
this mean that before I can start the migration I have to upgrade my zen
6.5 environment? I have not upgraded the zen 6.5 software because we have
started using the new zcm for "pieces" of our environment. We still need
the old Zen for the time being but I hadn't planned on updating it. Just
wanted to let it go and it would eventually disappear.

Any advice?