I don’t think we have a reason to worry. Capitalism will gladly fill out any demand with replacement products, the only thing needed is demand and smell of profits.
Even more, the new tube technology is coming. Check it out:
Tubes becoming hard to get?
An article in today’s WSJ talks about tubes for both guitar amps and stereo gear becoming scarce due to Far East and Ukraine/Russian tensions saying most tubes originate from China, Slovakia, & Russia. As such, people are beginning to Hoard and retailers are beginning to limit purchases.