Because no data is available for these aircrafts especially the a350 hence, I see it's really a wise decision from Aerosoft to make the a330neo version. If you think about it, Would you do the a320neo or any aircraft belongs to a320 family? surely not because lots of these aircrafts had been made why do you want to make something that is already available and most people had flown them hundreds and thousands of times. In order to, sell your aircraft it should be something new or special like when you compare Fenix to Flybywire. The a330neo only has a one competitor which is the Headwind, and no guarantees that Headwind will do an amazing a330neo as expected by the simmers so why not for Aerosoft to compete Headwind on delivering better and more realistic a330neo? I don't why a bunch of people are against this project as it seems very promising and I'm very excited to it.
I would have loved to see the entire A330ceo family finished before the A330neo, with all engine variants and the -200. Or the A340 if not. But well, I assume that developing a good A330neo from the A330-300 will be easy and fast, so let’s give Aerosoft a vote of confidence. If they think they have enough info to sim a good A330neo engine behavior I guess they can get good or even better info for the other engines of the A330ceo. I really wanna fly Iberia's A330 with their proper engine, instead of flying with a fake livery over the A330-300 with Trents like I had to do in P3D. I guess that developing all the family for P3D made little sense once MSFS was announced and released, but in this point with MSFS positioned as the simulator of the future for many years to come, it makes all the sense finishing the family for it. So let’s trust that all this development will finish with a complete A330 family as expansions in the near future. That would be an incredible addition to MSFS