FR can differentiate between the two models by using different prices, for example BRU-FCO will cost more than CRL-CIA, and more convenient flight times.Can they operate at a higher level of expenses and still be as profitable, ie move towards a less extreme WN (Southwest) business model or are they risking to loose the baseline customers who are plenty but pay little, in an attempt to win the more lucrative ones who pay more but are fewer?
They will be using the same planes so if there is the demand they could easily evolve into a 2-tier system; Ryanair Traditional and Ryanair Upmarket.
If it doesn't work they can go back to their standard ULCC model.
The important thing is they are experimenting with new ideas; who knows where it will lead?