Trying to figure things out: we end-up with compromises like below?
Option #1 contains:
* Same complex components, waiting that they become available again
* Uncertainty about when the next component will be available
* Alternative compatible passives
Option #2 contains:
* Another complex component slightly incompatible
* Extra engineering time to port the project to the new component
* Alternative compatible passives
Option #3 contains:
* Stop production of that product altogether, focus on the next iteration
* Extra engineering time for the new product, eventually planned already
* Picking components among those available
Option #4 contains:
* In case of availability at a higher price, pay the extra price to still be able to produce without a redesign
* Uncertainty about how long the priucier component will be available
* Alternative compatible passives
Option #5 contains:
* No reaction, letting the doubt settle about everything
(Not a real "option", but would probably happen in spite of any option chosen.)
I'd go option 4 and then work toward redesigning with available parts(purchase as you place them on the layout) and design in alternate footprints so you have better flexibility if parts become unavailable again.
I just bought some parts from a company for about 10 times what I used to pay for them while they were being manufactured(no longer manufactured, obsolete, no alternatives) but without them I can't do my work, so just had to cop it.