My money is on the latter. The whole "summoning Rezuul" has been a running gag among the jong vtubers for a while, so he probably got self-conscious when people started to blow it out of proportions.Maybe it's because it makes him look desperate, kind of creepy and actually schizo. If it was actually a clip he deleted then it just makes it seem like he knows it's weird and something he is trying to hide. If he deleted it after seeing it on /pcg/ that would make it even MORE cringe but also funny that Pippa was able to see it.
And I disagree with the clout-chaser allegations. If that was the case I am certain Pippa woulda told him to seriously fuck off. They are both on the joke and its just spergs making a mountain out of a molehill.