Interesting that you think it's interesting. If there ever was a place for it, this would be it. I would personally prefer them doing it on their blog than being interrupted in the docs. At least I know what I am getting with the blog.
Where would your preference be for their monetization strategy?
Maybe it can be done well, but the Stack Overflow experience wasn't great. It's just filled with junk paid promotion articles and I avoid it completely now. Maybe the blog is useful for marketing their products, but IMO it's definitely damaged their brand value.
Donations is a bit of a cop-out answer I know, but it can work for reference works. I wouldn't want Wikipedia to fund itself with sponsored articles.
It is apparent that the reference page lacks any mention of features from level 4 such as oklch, display-p3, and color function. Also, a search for "display-p3" in the search bar returns no result on that page.
You’re looking at the reference page for the ‘color’ property, but that’s the wrong thing: all this stuff belongs on the page for the <color> data type; and that’s where it’s found: https://developer.mozilla.org/en-US/docs/Web/CSS/color_value. Frankly, I’d prefer the color property page (and background-color, and border-color, and …) to deliberately not have so many diverse examples, and link much more prominently to the <color> page.
You're right. I am not as familiar with MDN's organization and CSS as you are (I only recently discovered that CSS is a typed language). However, I find it confusing that some pages have their own page for values, while others don't. As a reference page, I expect the valid syntax for all values to be provided. But I agree that specific examples can be linked to other resources.
Things like colours and units get used in many properties (color, background-color, border-color, box-shadow—in which <color> is only a part of the syntax—and many more; width, length, font-size, font—a shorthand in which <length> is only a part—and many more), and if they get expanded in one place, then all properties that use them take the new definition—hence <color>, <length>, &c. as the only sensible way to structure things (in spec, reference and mental model). By contrast, the values of properties like ‘display’ aren’t used anywhere else.
It sounds like a large part of the problem is helping to build the right mental model. If you understand that colours and lengths are used in many places, it will make sense that they will be documented separately from the properties, and that the properties’ references will just refer to them.
Listen here, you. I want my Mozilla monetizations to be IN MY FACE, in-browser advertising overlays for their latest branded non-Firefox offering, while I'm trying to browse on an unrelated website.
I find it amusing that even when you're on the MDN Blog URL (https://developer.mozilla.org/en-US/blog/), it still shows you a banner on the top that says "Discover the latest web development insights on our new MDN Blog", which links to the exact same page. :)
MDN has the advantage of being more accessible (!mdn bang on DuckDuckGo, Dash docsets) but I prefer O'Reilly's Pocket References, although they may be a tad out of date.
Interesting that they'll have sponsored posts.