As a fan of TF2 this caught my attention. I haven't yet played Splatoon myself so I can't compare that well but it seems like an interesting mod for sure. Might be a bit of fun and with a bit more polish and attention it could get enough players to have some regular servers set up with this mod.
If you're interested, check out some of that YouTuber's other videos for some other TF2 mods such as SSB and an adventure mode for TF2 that they're working on.