Exactly, all the later languages that were made to replace C++ (Swift, Rust, Zig) all rely on LLVM, so it has become a much more important project than in the past. (And I'll bet Google's new Carbon language will also rely on LLVM.) It's just that it's so hard and time-consuming to write a compiler backend with all the latest optimization techniques, and GCC's backend isn't as much as flexible than what LLVM brings to the table.
LLVM is very much alive at all big tech, to my best knowledge. It's C++ that's dying there (and I say - good riddance).