I will stand by my Astel Ollie ship.
If it was just them playing Apex together that one time, sure.
It it was just the fact that they started playing Apex together kind of often, okay.
She starts calling him her "Aniki", well ok.
She starts saying she wants to do duet karaoke with him using Disney songs.
She Freudian slips and calls him "Oniichan" during Apex, and gets rage-embarassed about it during the post-stream.
And now he's starting out his "No guys she's just like my sister!" followed with "...but she's like the only woman I feel like I can talk to." in the same breath.
All I have on Fubuki and Oga is that he's the only male she collabs with on a regular basis, so I could go either way on it, I'd be more surprised to hear they weren't going out, but it wouldn't take much to convince me either direction.