"Three sections of linear algebra? By one instructor? I’m guessing it was pretty watered down."
I'd suggest that the lesson plans for Linear Algebra rarely need to be updated based on current events or new discoveries in the field.
I think that linear algebra is a very active field in maths, if not the most active. Especially right now as the deep learning algorithms use it extensively. No there seems like lots of new exciting discovers have been coming out of linear algebra for at least the last 5 years probably closer to 10. These aren't necessarily just faster algorithms either but deep insights. Although the faster algorithms is a big deal too. As you might guess I like linear algebra, terrible at it, but man is it cool.
As far as teaching it - there does seem to be several ways of going about each which take awhile for students to understand why it is so powerful and get bogged down in the mechanics of matrix vector multipication and miss what its can do and model - There is no royal road to mathematics