Open Source is more like a designation. It is an agreed upon set of requirements that, if you change a requirement, it is something else. This is important.
Some things have legally protected designations such as 'ice cream'. Ice Cream has specific meaning in industry and even a grading system. If someone wants to make a cheaper product than the lowest grade of ice cream, they can't call it ice cream, they have to call it something like: frozen dairy dessert.
This makes it easy for people understand what they are actually getting and paying for.
I wouldn't get indignant about mandating english language definitions. I would be indignant that ai companies are not fulfilling the requirements to call it open source and are providing a cheaper product than the abilities that an actual open source model would provide.
It also has an obvious english meaning. The source of the model isn’t fully open, it is not possible to inspect and modify the input used to build the models.
Who is this organisation that they get to mandate the definition of the english language?