Hi beejaybee. Citing a potential conflict between PanF and the proposed Delta 25 comes straight from Simon Galley, of Ilford. It is included in a (lengthy) thread on APUG. Simon stated that the likely volume of sales would make recovering R&D investment difficult, especially if PanF users simply switched film.
Now, this may or may not all be true, but that is what he said. Personally, I shoot several Ilford films. Currently I use FP4 ONLY in 5x4. Why? For 35mm I want fast film I can hand hold, so I use HP5. In 120 I use a tripod, so I shoot PanF to get its fine tones. In 5x4 everything has to be tripod mounted, so I'd like the sowest, finest film I can find. Unfortunately, PanF will NOT be made available in sheets. As a result I shoot FP4 because that's what's available.
If Delta 25 came along, and proved to look anything like PanF, I'd drop FP4 in a flash. As an amateur the greatest limit on my photography is time- the total volume of film I shoot wouldn't (significantly) increase just because there were more film stocks to try.
Perhaps Ilford heard other people saying the same thing.
Lets be honest. If you could make a million pounds by selling one product, or make a million by selling twenty products, what would you be inclined to do?
Right now I'm VERY happy to get 120 PanF, and I'm building a little stash 'just in case'. There are lots of others I'm enjoying experimenting with (just 'discovered' Delta 3200) but for me, the very last film I want to loose is PanF.
All the best.