This plugin has a GPL license which means that the author has to either change the license to MIT or remove the license entirely before Indigo will add it to the Open Source plugin library. Otherwise, another developer will have to fork the plugin and continue with the existing license. I believe that Matt & Jay have reached out to TwitchCaptain but, as far as I know, they haven't heard back.
I came here to drink milk and kick ass....and I've just finished my milk.
Licensing on this plugin is especially odd since it's licensed with GPL 2 but it contains GPL 3 library. Given the scattered interpretations of GPL licenses in general, we avoid putting those into our open source repo. This does not mean that it can't be forked and updated as Dave points out - but whomever does it would need to host it themselves. We can make the appropriate adjustments in the plugin store if someone were to do that to make any updates available.
I will also point out that the current version is using a 5 year old library for the Broadlink devices. There is a current version of that library, that supports many more devices, but is considerably more complicated. Between that and the license issue, it would probably be easier to start over using the current library.
This has been one of those plug-ins keeping me from updating to 2023- I was surprised how straightforward it was with the Hardware and I am now someone dependent on it.