No worries, I think I get what you're asking, and it's something I've discussed in other places, like Discord, but not so much here.
Anyway, I think Phantom is an interesting show in that it's so old, and the people in charge of copyright striking bootlegs are so lax, that I think there's less fuss in general about people uploading clips or even the full show to YouTube compared to newer shows where the creators are more likely to go after bootlegs and their recorders. So yes, it should count as a "leak", but as the saying goes - if a bootleg is uploaded and the filmer is no longer around, does it create any sort of trouble for them?
Another thing too is that many of the original filmers have long since left trading and unlikely to care what happens to their videos, which again, is just because Phantom is an older show (I know of one Phantom filmer who has actually passed away, that's how old some filmers are). It also helps that Phantom has had many international productions that closed years ago, which again, means it's less likely that there's anybody in the company who's going to come after a bootleg being uploaded. Like, do we really think the original Hamburg production, which closed in 2001, is going to go after the filmer of a bootleg from 1997? Probably not, so nobody's really going to be be a bother if you upload a video of it.
(Incidentally, this is also probably why members of the cast and crew will start leaking audios and videos - after enough time has passed, who cares? I'm almost certain the Mexico City proshot of Phantom was from a cast or crew member, as was the monitor video of the original Stockholm production, and I think everyone knows by now that it was Anton Zetterholm himself who decided to toss out the proshot of the Stockholm revival.)
Additionally, other filmers might be around but are not on social media because again, an older show means an older generation of filmers, meaning even if they did care about their stuff getting uploaded, well, it's unlikely they'll find out. Compare this to a musical like Six the Musical where the fans tend to be newer and younger, meaning it's very likely that the filmers are newer and younger, are still in the trading and bootlegging scene, are very active and adept at moving about on social media, and will take serious umbrage if you go uploading their stuff, especially combined with the fact that the company is more likely to come after them for bootlegging.
And yes, with some bootlegs, they have been uploaded so much it feels like you're fighting against the current to even go against it, especially when there are no repercussions. For example, the video of the original Broadway cast of Phantom has been posted so much, and by multiple people, that I don't think anybody cares at this point. That can certainly count as what you might consider "public domain" videos in that so many people have it, have uploaded it, or have seen it, that it's just taken as a free for all, do-what-you-want video.
That said, there are some unofficial rules that people tend to follow. Stuff filmed by people who are still active in the trading scene tends to not get uploaded. Stuff from post 2019 or so is a bit uncommon, again tying into the fact that people who filmed more recent boots are still very much around. If a filmer asks you to take something down, take it down. Name it something obscure (but that does not involve the words "slime tutorial" anywhere).
Anyway, I hope that answers your question!