Let's try to be optimist.
This news can actually improve the probabilities that Fuji can go on producing slide film waiting for demand to recover (a new interest for analogue, for slide projections, sometime in the future);
Same can be said for Agfa, the only other colour material producer left;
Somebody might acquire Kodak machines, technologies and patents relating to E-6 products and start a new business venture. This is not necessarily impossible. Present day Kodak is in a situation where they cannot devote money and energies to reinvent this market. A new venture focused on doing this might instead succeed.
Slide film was in any case a very small volume of sales for Kodak. PE said already years ago that E-6 would have been the first to go. Negative materials (both colour and black & white) sell many times more than slide film.
E-6 processing, as opposed to Kodachrome processing, is something that every small laboratory can do, and even amateurs at home can do. Sending by mail a roll and receiving the slides back was usual practice in many countries several years ago. Processing should go on without a problem, at least in countries with an efficient mail system.
Let's not forget how mechanical watches recovered after the years in which quartz seemed to have killed them. That's even more striking than the vinyl resurgence IMO.