I think that something is being missed here. TowerJazz is the manufacturer - the FAB. That does not mean what they produce is going to be available for general sale. Who owns the sensor's design? The sensors going into the Leica bodies isn't available and the indication in the various news articles has the sensor in the Nikon D850 being a Nikon design for the most part. I really doubt that Nikon is going to make their designs available to Pentax, Fuji, Olympus, el al. Also, Nikon has the production scale - something that Pentax lacks.
That leaves Pentax either staying with Sony or doing their own design (to some degree). Now, semiconductor design today is not like it was yesterday where you need to be an expert at everything. You can license the IP packages. What that means is that they licensed a number of IP packages, the copper writing, the BSI, the dual gain, probably the sensels, etc., from other folks - there are lots of these available. You can even hire a custom semiconductor design house for the layout and to roll it for you. It all comes down to dollar$ - what is cheaper and more efficient for what you need.
The profitability is in the scaling of the sensor fabrication. The more parts you make, the more you can reduce your cost$. Sony by FABing the sensors for everyone was essentially capping their costs to a large degree. Intel has demonstrated this on steroids by even now going out and FABing ARM processors for anyone who has the need for large production runs.
Will this put pressure on Sony to be a bit more nimble with their product offerings and pricing - well one would think, however to what degree, I don't know. That all remains to be seen.
I've read rumors that Asahi or Pentax back in the day, went to a small custom design shop for their famous SMC lens coatings. What Pentax does in the future is still unknown.