There isn't really any cases of Ralph blackmailing anyone. Just assumptions as to why some people are loyal despite many jumping ship, like Dame, without any repercussions at all. If any blackmail was going to come out it would've happened during the pillstream. No, Ralph mentioning Rand's embarrassing stream after Rand tried to embarrass Ralph about him supposedly crying isn't blackmail.
Hasn't he though?
Threatening to release embarrassing info on Randbot unless he submits to Ralph
Threatening to dox Adezero unless she does as he says
Threatening Vickers to "make him famous" unless he backs off and let's Ralph do whatever he wants
Threatening multiple people (from viewers of the show to women who won't do what he wants) with similar threats ("make famous"/"exposing"/etc.) or just outright dox them in a fit of rage (Lord Akira)
Openly asking people to send him dirt on anyone that pissed him off to "expose" them, forcing those people to either quit doing whatever is bothering Ralph or to suffer whatever hit piece he was able to muster up for the few people that read his site
Using Zoom to gather dox/info on anyone that crossed him during he stream.me days
Using whatever power he had on stream.me to keep people in check or do as he wanted
He was much more open with these kinds of threats during GG, both on twitter and while drunk on stream. People
mostly never cared since he went after anti-GG people (again, for the most part), but he has always had this tactic of gathering dirt on people to use against them, either openly or privately.
Maybe it could be classified as something other than blackmail but it comes down to Ralph
always gathering dirt, information, recordings or anything else that he might be able to use against other people and keeping it until he needs it. This includes lovers, friends, supporters and enemies alike. It doesn't matter, he will save the information because he knows that at one point or another all his relationships end up badly so he might as well have something he can use.
It wouldn't surprise me if it is confirmed that he is holding something over Gator's to keep him in check, but at the same time, Gator is so pathetic that it's not just about that, he goes well beyond the limits of someone being "forced to" do things for Ralph, he does everything in his power to keep Ralph happy, whether he does it because he is afraid, because he has some type of hidden agenda for taking over Ralph's show or because he is just so pathetic that the KS and anime are the only things that keep him going, I can't say, but none of those options make him look good.