I have to wonder how far the San’layn working with the Horde news went. It’s possible Sylvanas kept working with Dreven mostly a secret, and that Rokkhan knew because he was stationed at the outpost in Nazmir. Talanji knew because she was there as well. I don’t know if anyone other members of the Horde knew unless Rokkhan or any of the grunts at the outpost mentioned it to others.
The thing to note with this is that this was done from the point of view from the Alliance, so of course the San’layn appear mean, bad, and scary. We don’t really have much to go on of how Dreven’s coven was personality-wise outside of what we see. Yes, he did munch on some Forsaken, but we don’t know if that was out of desperation, whether the Forsaken there were Sylvanas loyalists, or whatnot. It’s possible he was a power-hungry jerk that just didn’t care, but it’s hard to see all of the San’layn with a similar personality, especially since they’re technically freed from Arthas, so you’d think they would have some semblance of their previous personalities back. It’s unclear if any of the events were recorded there also, since it isn’t mentioned at all from the Horde questlione.
Even if Dreven was low on moral fiber, if San’layn in general were trying to join the Horde and reconnect with Silvermoon, I don’t see why Thrall or Lor’themar would turn them away. Surely, some of the Horde would know that they were similar to the Forsaken and then got their free will. Even Rokkhan seemed cool with it if Dreven’s coven was willing to work with the Horde.
Sure, some of the Horde may be dubious. Talanji would need to see the true meaning of Winter Veil especially, but that could tie into the reintroduction of the San’layn. Put them in a storyline and give a reason that the Horde needs their help with the San’layn wanting to both join the Horde and survive in a world that is against them. Make them united with the Horde when their allied race unlock scenario comes up, and there is a lot to work with there.
The only thing I can really think of in terms of current San’layn acting the way they do still might be something related to the vampyr curse. If such a thing is possible, then hey, we got another storyline to work with to free the San’layn and have them join the Horde that way.
The thing is that there is a lot of potential with what you can work with in making San’layn a playable race. I honestly see no reason why they wouldn’t be given a chance like with the Forsaken. There are likely a lot of San’layn around still, not sure what to do, and we don’t know the extent of what Sylvanas did to work with San’layn. let alone how many San’layn she worked with.
And besides, with Sylvanas out of the Horde and likely not coming back anytime soon, I feel like San’layn would get treated much better without her being there. She likely was just going to use them for her own gains.
Anyway, as myself and others have talked about, San’layn are much more than just mooks that are scary and mean just for the sake of it. If we’re letting Undead Humans and Death Knights into the Horde ranks, I really don’t see why San’layn would be such an impossibility.
I’m sure I could write more, but that’s all I can think of currently. As such, I’ll continue to give my support for them as a playable Horde race. 
Granted, there’s many videos of people making fun of roleplaying, but I plan on making a combination of videos, informative & fun. So people can deal.
it’ll keep the spirit going I’m sure. A dark rangers video sounds like a glorious idea. If Balesong wants, I’d love to do that for them. And credit the ideas to them.
