Aside from scratch, finding device to read/play it shouldn't be hard since you could use any DVD/BD reader. I expect few company will continue to make DVD/BD reader in the future.
Nobody is making devices like that anymore, except maybe in China and North Korea, they are probably sill making VHS players also. 
You can't find cd players on computers, laptops, in cars and I don't remember the last time I, or someone else I know, used a CD disc for anything.
In theory they can work in future, same as gramophones work to play music.
Blaustahl USB really looks very interesting for storing seed phrases, considering that the device has a built-in text editor, accessible via PuTTY и Tera Term, the memory capacity is enough for this, and the device has a long resource for reliability and durability.
I wouldn't use it for that purpose until they add encryption, but users can do manual encryption if they want.Not sure about their 200 year service life warranty but it sounds interesting.
Stainless steel will probably survive longer as a backup.