To me at least, a definition of "light" that only covers games up to 6 pages is so narrow as to be unusable. I'd suggest "ultra-light" or something for that, to indicate that it goes beyond the "normal" light. It's like saying that to be considered "light", a vehicle has to weigh about the same as a bike or less.
Well, that's why I made sure to say what it meant to me.
Look, these are arbitrary definitions. There is no set meaning. For example, someone who is all like, "I play all the TTRPGs, from Pathfinder to D&D!!!!!" the idea that a game has six pages or less of rules is probably bizarre.
But for someone who plays a lot of indie and bespoke light RPGs, the idea of trying to differentiate the games that have a lot of crunch between light, medium, and heavy also seems weird. They are all crunchy. A little more or less doesn't really make a difference.*
Light, to me, means just that- light. And I think it's important to make this distinction, simply because so many people are used to the rules-heavy games that they aren't able to understand how truly light RPGs exist- as they have since the beginning.
*Okay, there are some games with obscene amounts of crunch, or that are infamous for the difficulty. Phoenix Command? But I think that trying to divide up already crunchy games into smaller segments is fairly uninteresting.