Probably because of Suho's storyline about his best friend in his band (Seyeon) died. It feels more heavy now because Cha Eun Woo's real life best friend in his band, Astro, also passed away.
The ending is open, but it is assumed to be a hopeful/happy one. There is someone who likes Yetan, but they don't cause any drama, and she's very clear about her feelings. Same with Qingkui. They both like their respective MLs.