There is currently no official announccement.
Since co-chains are not fully specified, it is not completely clear what the best option is.
If you create a private network now, you may need to reset it completely to make it a co-chain. This is not an issue as you can always make a snapshot of a private network and use it as genesis of another private network / co-chain.
It depends a lot on the way it is implemented.
I guess that there may be a way to make it compatible.
See Distribute participation reward to ASA - #2 by fabrice
But since co-chains are not yet available, it is hard to know whether it would be possible.