AptX (even the non-LL one) is the only codec I know that has acceptable latency where it's even good enough for gaming.

Sony WH-1000XM3 had AptX, WH-1000XM4 does not and other latest generation ANC headphones also do not.

So headphones from 5 years ago are more useful than modern ones. Modern ones are so bad, if you stop a song you hear the song still playing a bit after you pressed stop.

Might this open sourcing increase the likelihood of acceptable-latency first-tier ANC headphones again?

Or are they still going to be like "open source is too open, let's keep using my own high latency proprietary codec anyway and add a few ancient even higher latency ones like SBC for compatibility"