We don't know because we don't know how long the hiatus will be. It doesn't look good though. Maybe she gets replaced.
Sayaka talked about Yuuri in her showroom. It was kind of all over the place, as Showrooms normally go, but here's a summary.
So it sounds like it is more of a mental problem that is happening rather than a physical issue? Depression or anxiety maybe? Poor girl
Its hard to parse (and I'm sure they don't want us to parse) and it could very well be mental but it could also mean that she's getting stressed out by her physical problems which is why Sayaka told her to take a break.