As you know the government seems to be pushing electric and slowly moving away from gas so many brands are starting to introduce more induction options. 48 is still a tough size you did your correct homework. Fisher paykel is a great hybrid option, Fulgor the best for all induction and one of the newer one but service lacking at the moment. Bert due out in 3-6 months and does have a better service network. On the AGA I just dont love it, ovens small flimsy side panels and doesnt seem to be made as good as it looks.
Thermador just came out with a 36″ for now but I dont see a 48 from them for at least another year. No one else formally introduced any as of yet.
So Fulgor best for all and Fisher for a hybrid.. Bert when it comes out will be ok but prob priced in their range.
Although it appears that you have done a lot of research on 48″ induction ranges, you are still having trouble locating the best solutions. You have good reason to be concerned about the availability of parts and repairs for specific brands, such as Fulgor Milano and AGA.
Although it is an interesting possibility, the Fisher & Paykel model is somewhat expensive. Watching the future Bertazonni induction range could be worthwhile. Regarding your inquiries, it’s hard to forecast what other manufacturers will do in the future with relation to 48″ induction ranges, but you may monitor trade publications or get in touch with them directly for information.