Honestly, this would be the best case scenario and I could kind of see it.
Imagine it like this: Vesper and Magni are talking to each other, and in that discussion they both mention they want to take a vacation. One of them has a lightbulb go off and comes up with an amazing prank, and they mention it to Bettel, who loves it. Vesper and Magni convince management to have the odd message of them not streaming for a while, and go on their respective vacations.
They know that the sudden disappearance of both of them at once, along with the strange message from management, will get every vtuber fan going wild with theories. They'll be watching it all, laughing their asses off. Then, on the 19th of August, the appear on Bettel's stream, performing whatever end portion of this prank they came up with. After that, back to regular streaming.
Can you imagine someone trying to explain to Takeshi what "happening humor" is and what it entails.