I think it's worth it. I have a rudimentary understanding of C, but I still gained from it. The first few videos are about the project structure and the main Python loop. You get to disassemble some Python code into bytecode and see what's really going on. Don't let the lack of C expertise stop you.
It would take less than 10 hours to gain a similar understanding if you just sit down and read the source. The CPython source is surprisingly small. It's not without its warts, but it's laid out well enough.
Yes, this videos should help mostly in dealing with the trickiest parts like the async modules implemented in C, which is most efficient than reading then code in this case.
2015: https://news.ycombinator.com/item?id=10483857