Pippa herself admitted to it, but I forget if it was during her end of stream part or in the next stream. I think it was that stream after Koa left though. She was currently going through stages of grief over Tera's shut down being announced. Pretty sure that's part of what led to her streaming with Kirschey a day or few later too. I actually do remember finding some of the Koa collab funny, but Pippa went hard on some of the commentary and delved deep into shit quickly with Koa half the time not even getting a moment to consider things. This WAS a fair bit ago so I could recall parts of it wrong, but Pippa definitely was a bit sharper and harsher than usual in it. In fact come to think of it, I'm pretty sure that was a stream where Pippa was arguing with her about how romantic ryona was or some wild shit compared to ntr.
Edit: You added since I quoted while I was autisming, but I don't recall that part. I don't think that was a Koa reference if only because I'd be surprised if Pippa remembered much of the collab outside of feeling like an asshole over it later. Much less specifics of it. BUT I'm going off memory so this entire Pippa part could be retarded and wrong lmao.* I just know the piss bottle thing was brought up during a stream with Lisa and Pippa. But I thought it was just one of those random crazy bitches she knew online or in person growing up.