If it is leverage though, idk if there's a lot of canon possibilities. If it's something related to the DIKs in a general sense, the dorm girl posters already cover that (pissing in Tyballs' room). Can't be anything lewd, since Monk MCs are good boys. Maybe Rich buying drugs, but that's such a minor thing and I don't think Tyballs has a real problem with Rich. The knowledge that Sage is the troll account on Rooster is meaningless.
Someone floated the idea of pics of Bella at the Halloween party, but... ehhhhh. Idk, if someone has a good idea then I'm willing to put more stock into this being leverage.
Tybalt's letter is a big mystery. We know that the betas are behind it all and their aim is to get revenge on the other frats. Magnar does not mention the Eta Omicron Tau sorority and the girls aren't shown getting any letters so they probably aren't targets, but they might still have a place in the schemes.
Sage's Rooster antics are really the only canon thing that relates to Tybalt and isn't commonly known, but what do they hope to gain from telling him about it? They might be trying to keep Sage's hands full so she can't bring peace back the way she did earlier and that could have good results, but then what is there to take the preps down?
The alphas' letters aim is clearly to get them to attack the DIKs and get the DIKs to retaliate so both frats get suspended and the members expelled, but how is that supposed to get the preps in trouble? So Tybalt's letter has to be about the preps. The part about Sage may also be included as well as some optional content, but the rest has to result in some kind of infighting. We see the three freshmen disrespect Tybalt in a number of ways and that could be foreshadowing for what is in the letter. They have done something we don't yet know about that will make Tybalt mad. Or it could be about Rich's drug problems. Or both.
Or they could have given Tybalt proof of DIKs' drug abuse knowing that the investigation will also lead to Rich. But if they have that knowledge why not just go to the authorities directly and let the scandal take them down? I suppose they could just want complete anonymity in the matter or they are worried about getting hushed up, but getting an entitled spoiled brat to do it for them is less risky.
On the whole though, the big reveal of it all being betas' Revenge of the Nerds IRL enactment is pretty anti-climactic. It's just pathetic of them. I just hope that it leads to something more meaningful.
