I agree this side story could have been skipped and isn’t really necessary. But now it’s here and I think the author is just playing with our nerves.
So about the chapter, I think after the shock he just receved, Taesung will plan a terrible revenge on this piece of shit of a grandfather. I just hope there won’t be too much drama like a time skip or à love triangle with Haebom and his potential new (and kind) boyfriend...