I remember CS 61C at Berkeley used to use MIPS to teach assembly language programming and a bit about computer architecture, using the original MIPS version of Patterson and Hennessy's Computer Organization and Design. Now that book is available in both MIPS and RISC-V versions, with, I've assumed, much more effort going into the RISC-V version...

I do think the simplicity of MIPS was a big plus there, including simplicity of simulating it (http://spimsimulator.sourceforge.net/). I suppose a lot of students may appreciate being taught on something that is or is about to be very widely used, even if it's more complicated in various ways -- and the fact that one of the textbook authors was a main RISC-V designer makes me assume that educational aspects are not at all neglected in the RISC-V world.