OP, could you replace that “Slave” with “Slavic” in the title? It represents better the content of the video, including its title.

I’m watching it now, by the way. It’s about the impact of /VjV/→/V:/ contraction in the Western dialects of Common Slavic, and it claims that it’s a factor behind the fragmentation of Common Slavic. I’ll comment further as I finish watching this video.