Because obliques are difficult to deal with, offer an uncertain timetable, and can lead to setbacks. The Cardinals haven't offered a timeline for Mikolas or Hicks either, and that's the same thing. They've been prescribed a procedure and then rest, and then after that they'll know.
Look, with some injuries the moment they offer a timetable, that timetable is wrong because people heal at different rates, they have different positions, the injuries have the same name but different severity or location.
Flaherty has a torn oblique.
That has to heal. That has to recover. And depending on how long that takes for it to heal the team will know how long he'll need to resume throwing. Bake in a set-back, because again a torso injury is tricky, and they'll have some sense of his recovery. For every week he does not throw, it will likely take a week to regain that arm strength. So, he's set for several weeks of rest here. If he recovers at the end of that, you can do the math that he hasn't throw for two weeks or three weeks, he'll need two weeks or three weeks to rebuild arm strength.
I cannot stress enough two things:
1) Medical diagnoses are difficult, and don't come in bite-sized, made-for-Twitter givens. Each has some nuance that we as the media could do a better job explaining to readers, if those readers are genuinely interested.
2) Every team is dealing with injuries. It's an industry-wide concern this year.