There are 3 major tube suppliers, one in russia (electro harmonix- now closed), one in slavic republic, (J+J) (still open) and one in China (still open). There are couple small ones like Western Electric in the US (they build one or two hi fi tubes and that's it). 12 AX7s' in some form are important for audio in guitar amps, pro audio and more. I expect tube costs will skyrocket and new designs using tubes will get put on the shelf.
Demand for some of these tubes is so small that it's not enough to justify the product development costs much less a provide enough revenue to a business to run on.. The obscure tubes were being satisfied by NOS supplies, but now that is drying up.
Its going to be a issue.
Brad