It probably will. Every release has a number of performance improvements although the release notes don't mention them. Great work like [1] [2] [3] weren't mentioned in the release notes because those notes mostly focused on feature improvements.

This work seems to be gaining momentum, if anything. The next version (1.44) will significantly improve the performance of programs that use async [4]. The next version of LLVM will be faster [5] (hopefully reversing the perf regressions in LLVM 10).

[1] - https://blog.mozilla.org/nnethercote/2020/04/24/how-to-speed...

[2] - https://blog.mozilla.org/nnethercote/2019/12/11/how-to-speed...

[3] - https://blog.mozilla.org/nnethercote/2019/10/11/how-to-speed...

[4] - https://ferrous-systems.com/blog/stable-async-on-embedded/

[5] - https://nikic.github.io/2020/05/10/Make-LLVM-fast-again.html