I feel like the big takeaway of all of these videos is just "Never engage with the alt-right".
Broadly, yes.
But in the context of day-to-day discussion, these videos are more about reminding "people on the left"about the option of swiftly calling out and shutting down troll-argumentation.
Part of "being on the left" (or "being progressive") is largely about stifling your preconceptions. Or at the very least not give into your immediate irritation, and hear other people out.
The alt-right has intuitively understood that the most effective strategy to counter people who make a conscious effort is to dismiss the entire basis for conversation and argumentation.
It's pretty effective; both because it doesn't leave much for your opponent to work with, but also because so many young, opinionated "people on the left" have a personality-type that would rather go over a troll-post line-by-line, footnoting every fallacy with appropriate wikipedia-explainer-links, than just telling them that they're idiots who don't matter.
Obviously, the real challenge is to be able to differentiate between strangers with genuine unfamiliarity, and troll-activity meant to make you too tired to care anymore.
Unfortunately, I don't think there's any real separation between these two issues ("how do I appropriately deal with trolls without becoming a hair-triggered opinion-police?").
That's how I see these videos, anyway. The alt-right playbook isn't particularly clever or brimming with finesse. It's just extremely tedious to deal with because of how anarchic it is to open, earnest communication between strangers (which I guess is the fundamental of the Internet).
I see them more as a "hey, remember how dumb and paper-thin troll behavior is? Keep the content of this video in your semi-conscious-mind" rather than "ok, this is how you totally destroy the alt-right by pointing out how they aren't playing by the rules of your domain!".
I guess I see it as a kind of passive PSA for the in-group, rather than a manual for solving wide-spread garbage.