Nice video! I'm not the best person to ask because I already know 555s well, but just a few suggestions:
-- You didn't really explain the key property of a flip flop, which is that when R=0 & S=0, it remembers or maintains the previous state. This is pretty essential as it defines the difference between a 555 where the cap voltage is 1/2Vcc on the way up, vs 1/2Vcc on the way down. I think you ought to mention one of those "stateful" type keywords, or else you're making it sound like it's just some sort of weird logic gate that just outputs whatever S is.
-- Random note, you need a fullscreen HD to view the video, people on phones might have a hard time to make out the little diagram in the middle.
-- Also, this is much more a matter of opinion, but I think it's not a great idea to use plain boxes for comparators and flip flops. You don't even have the different inputs and outputs labelled, and if your viewers ever go to a real 555 datasheet, they won't recognise anything. I can see the counterargument that words are easier to recognize than shapes, but I'm not convinced. Also a matter of opinion: using a block diagram where the pins are "in the right place" is ill-advised, as the block diagram looks like spaghetti and doesn't flow from left to right like a nice schematic does. The counterargument that it's "easier" to map to a real chip is questionable in my mind, and also not exploited by your presentation in any case.
But I'm nitpicking!