We are on Ada 202x nowadays being discussed, and in a world where FOSS tool makers have problems making a sustainable business, always changing licenses, there are still 7 Ada vendors selling compilers.
And only AdaCore / GNAT will ever support Ada 202x. The language has left the legacy vendors behind.
Libre compilers do not impose restrictions on output.
In embedded world restrictions on the output is the last thing of worries while fulfilling various certification requirements can be a big and costly headache.
And from the vendor point of view releasing a compiler under libre license allows for concurrents to undercut one on R&D leading to the compiler and related tools certification. So from business point of view it just makes no sense. This is very different from contributing to, say, clang, where a cost of maintaining own closed fork outweighs any disadvantages of contributing.
As long as there are enough people around to actually work on them.
I personally think that AdaCore, and friends, missed an opportunity in the early 2000's to fully embrace open source... they left a big gap which Rust has filled nicely.
I still think Ada is a great programming language. When a question comes up along the lines of: "what's the best programming language nobody's heard of?", or "what's the best programming language that is under used?" Ada is usually my first answer. I think other good answers include F#, <insert LISP flavor>, Odin, Prolog, Haxe, and Futhark (if you're into that sort of thing).