At the time your post here said “Our definition of Open-source follows the OSI definition” but I see that pull request was recently closed.
If the project wants to evaluate whether the open-source criterion should be changed to source-available, that is one thing, but it makes little sense to change the agreed-upon definition of open-source (not to mention the confusion it would cause). Even projects like FUTO accept the OSI definition of open-source and instead market themselves as source-available or source-first.