You think she's overdosing in a love hotel? Then again, if that's the case, how would Yumi even be aware of that. It would be a really new low for Yuki to call Yumi to witness it.
Or maybe Yumi's so broken from seeing her mother in such a state that she leads Akira to "comfort" her? These are two weird scenarios imo. The only other character that would be involved in love hotels is Noriko, from having a get together there with Kirin - but I'd doubt she tell Yumi to drag Akira there to meet her or something.
We know she's relapsing.
We know that she'd had enough recent contact with the Yakuza that the goons who harass Io are afraid of her on sight.
We know Yuki is missing a lot of work, so the bar isn't gonna provide enough income to keep her housed and drugged.
We know a love motel is involved in Yumi's content this update.
Prostitution happens at love motels, and "woman turns to prostitution to fund a drug habit" is a pretty common trope.
We're very clearly being guided towards "Yuki in crisis," and doing that right before a large Yumi update and not having those arcs intersect would be a weird choice. Sure, Yumi doesn't know yet -- but it's very reasonable to predict that she'll find out this update. Maybe Io mentions something, maybe Yuki (or someone in the Yakuza) calls Yumi. Maybe Yuki calls Akira while he's creeping on Yumi and that's how Yumi finds out.