I never learned HIE type emulsions from P.E though ide have loved to. P.E has been instrumental with guidance and expertise to me on many other things. I am lucky enough to have hundreds upon hundreds of rolls of HIE and EIR in deep deep freeze. but in saying this, it was a film i loved and I supported it by buying large quantities. (its a shame others didnt do the same or it might still be with us) I also have a few hundred sheets of HIE in 4x5" so meh I don't care for the prospect of Ilford making a new true infra red film. I also get pleasure knowing if I use my reserve of this film in the future in contemporary ways I will be able to achieve imagery with looks others can not.
If I was Ilford I would be very very wary of venturing into true Infra Red. The cost of R&D and production of the film versus the profits from quantity sold would have to be taken into extreme consideration. I feel although loved, these types of films have been discontinued for good reason. When I ask the bulk of people who love these films how much they would be willing to spend to buy a roll and how many rolls they would realistically shoot per year I would advise Ilford to snuff out any talk of such films being resurrected. Sorry to throw the unexpected out there.