In this first round with 2.5 and 21.02 there is no issue from switching, my take is same as moving from CE to FE now..
As it evolves - maybe that changes? The code base is for sure going to diverge. What happens to the ability to easy switch between the two as that happens, not sure.
I would think they would want to keep that ability.. Especially if used in some business setting where they wouldn't be able to use the free home/lab version. I would take it they would want to make it simple for the business to migrate from CE to +
One of the things that is coming is easy management for business of multiple units, zero config sort of setups.. Where you plug it in and it gets its config, etc. So my guess would be moving from CE to + will be easy. As to moving from + to CE a few versions down the road.. Not sure.
My take from the information I was given, this is more of announcement of change, when this happens next month.. I didn't get the impression that there is going to be really much different from CE and + in the first round. Just like there is isn't much different now between CE and FE other than a few extra tools, and some optimization stuff for their equipment, etc.