One recent change in the 3D Warehouse is that for Windows users of 2016 and earlier, the integrated Internet Explorer isn’t supported anymore. That is, the site code is using HTML features that won’t work in IE. You’re on Mac, so you don’t have that problem.
Another thing, which isn’t a change, is that for all newer models the warehouse only offers the last three versions of SketchUp as a download format. You still usually have Collada or KMZ as options, and those would work fine in SketchUp 8.
Searches in the Components panel continue to work well. I tried this model as a test:
https://3dwarehouse.sketchup.com/model/a9d4f3ed4c3d1e45ad2751f029cdb870/google-sketchup-8
and can find it using the Components panel, and insert it into a SketchUp 2016 document. The nice thing about using the Components panel for searching is that you’re only shown models that are going to work ok in the version you are using. I do have SketchUp 8 installed, but I’m running macOS 10.15 (Catalina), and all applications that old don’t run. I’m going to set up a virtual machine with an older Mac OS, so I can continue to test those things.
On the question of honoring a SketchUp 8 Pro license (though it could also be a 6 or 7, those were the versions made at Google), as with the 3D Warehouse, support only goes back three versions, and 8 is seven versions ago. For the Pro license itself, if you have not been under support for over three years, and want to get up to date, you have to buy a new license.
About the hiring people who don’t care, you don’t have an easy way to know who is who in the forum, but a lot of the SketchUp team post answers, and several of them are actually senior managers, responsible for all areas of the product, including 3D Warehouse. Pretty sure we all care a lot.