History has proven that system programming language winners come with an OS/platform to cimment their advantage over others.
So I don't agree that the age of "The age of multi-vendored languages like C or C++ for systems programming might be coming to an end.", unless you mean we will managed to get rid of all OSes written in them, specially UNIX flavours or GPGPU libraries.
It would be nice, but it won't happen until the next big hardware revolution like Quantic computers being developed in Q# for example.
So I don't agree that the age of "The age of multi-vendored languages like C or C++ for systems programming might be coming to an end.", unless you mean we will managed to get rid of all OSes written in them, specially UNIX flavours or GPGPU libraries.
It would be nice, but it won't happen until the next big hardware revolution like Quantic computers being developed in Q# for example.