There's no emulator that can run a Linear B parser. If a linear B dictionary ever existed, it was never mass produced. Linear B is older than the printing press, let alone the Internet. But now we do have those technologies, and "lots of copies makes stuff safe" is cheaper and easier than ever. I don't believe any mainstream digital format (i.e. popular enough to have a Wikipedia page) will be permanently lost unless there's a complete collapse of society, and then we'll have bigger problems to worry about.