FR may be the daddy in Europe, but their biz model is still heavily based on WN. To date, neither airline has ordered (I know FR had some 2nd hand 1-11s) outside the 737 range - of course that isn't to say a 737 is pre-requisite for loco ops, but it does say a lot for the single-fleet argument.
My guess would be that Boeing don't need to offer anywhere near the same discount as previously, as there are numerous growth markets right now which are hungry for frames, but MOL will still never pay list.
Ultimately, my suspicion is that the desire to keep to one type will weigh heavily against the new a/c. Of course, an unproven a/c is alaways a risk, but you are generally dealing with low probabilities here which are hard to quantify in a purchasing decision. Even if FR do suffer another hull-loss (can you say a 1 in xx year event, where x > 10?), they would only have confidence issues if the cause of the incident were the airframe itself -
afaik less than 20% of accidents? Incident at CIA was a birdstrike & also no fatalities so if anything a
PR win for FR, albeit much less so than the Miracle on the Hudson!