I agree with everything you’ve said.
If you’re interested in .NET and Angular together… the course “Build a Real-world App with ASP .NET Core 1.0+ and Angular 2+” is very good and I think you’ll like it for the same reasons you stated that you like Mosh as a teacher. For the most part, the .NET Core stuff will need minimal updates to work under .NET Core 3 or 5 (current version). The Angular was version 2, the last time I looked at the course, so you’ll probably run into similar problems with HttpClientModule replacing HttpModule.
In my opinion, it’s hard to keep old courses up to date, because unlike a book or a blog post, you can’t just have someone different come along and do a voice-over or re-record a video. In order to update something like the Angular 4 course, Mosh would potentially have to re-record entire Sections (to migrate from HttpModule to HttpClientModule), and might want to end up re-recording the entire Course to keep everything consistent.
I’m pretty sure that Mosh hires people to write content for his blog over at: https://programmingwithmosh.com/
Right now I think every course on this site is done by Mosh (hence “Code with Mosh”) and I’m not sure if that’s going to change anytime soon? I don’t think Mosh posts here a lot on this forum, but I could be wrong about that also?