This doesn’t make sense as the compilers would also be included in this new copyright scheme and would become public property after so much time.
There are open source compilers for all major CPU architectures. In fact the open source compilers regularly outperform the closed source ones. It’s also not exactly that difficult to add on more architectures to an existing compiler these days thanks to the modular way modern compilers are built. Once you build a backend for LLVM you unlock not just one language but about a dozen.