Sorry for late reply. I've no idea about the ending because I don't really know who is the real author for Grapara's ending now. The vibe is it's not Airi Katsura (sensei) anymore.
If Airi Katsura (sensei) was kicked out and Keishi Nishikida sensei (whose works are all rom-coms with happy ending, MC x FMC) took over chapter 134-136, it makes sense and you guys can trust him.
Keishi Nishikida sensei always gave the epilogue, he gave the best paths for supporting characters as well.
For me, I want all Sakura Shinobu and Fumi to be happy, so I prefer the harem ending though it seems to be impossible.
My view on characters in chapter 134 as the author wants :
Sukura told Mio she didn't know how to live without Shinobu by her side then Mio switched to ask what fucboy said to her. I don't think Mio shew up in chapter 133 and 134 then will do nothing in chapter 135 and 136 but we all see Sakura will switch agencies to join Mio. She can return to stay at the house after meeting with Shinobu (if) regardless their relationship because she's free from fucboy now. We can foresee Sakura's career but we don't know how her love will be. She still loves Shinobu but she'll do nothing about it !
Shinobu still loves Sakura but the same as Sakura that he'll do nothing about it because he thinks she's happy with her job and fucboy. He like Fumi but it's not love. We've only 2 chapters and it's not enough to show the development from like to love. The only way to end up with Fumi is to use the time skip. Shinobu always think of Sakura when he saw Fumi and compare them till now. Fumi is like the upgrade version of Sakura in his eyes. He didn't want Fumi to perform in the love scene because of his concern for her, not his love for her. Shinobu is a nice guy by nature.
Fumi loves Shinobu but she knows she can't replace Sakura. Shinobu may take the responsibility after taking her virginity but he still keeps thinking of Sakura. Fumi still calls him "director" that means there is still a gap in their relationship and they're not dating yet. They just start a love relationship and it takes time to grow. I didn't say Fumi was a bad girl but she also took advantage on Shinobu after knowing that he became single to confess her love to him. Shinobu didn't reply to her confession and then she asked him to have sex for the sake of writing a script. To start a relationship like this, it takes time for Shinobu to develop a love feeling for her. In chapter 134, she behave like a supporting character to me.
The question is whether Shinobu and Sakura will meet in the remaining 2 chapters? If yes, Mio may be the key.
As far as I’m concerned, if they just re-drew a few panels in chapter 129, everyone will not be headache and every problems will be vanished. LOL
Sakura and fucboy wouldn't be hated anymore. In chapter 130, fucboy lied that he had sex with Sakura. It'll be a win-win situation for everyone. The readers will be satisfied.
It’s just Airi Katsura (sensei)’s ego and lack of intelligence that refuse to solve the problem with this easiest way.
They can't do that with 2 chapters left as they're so precious. Anyway, I'm confident they'll give us a bonus chapter 133.5 full of sex scenes. LOL