This is what I'd expect having worked for ~10 years in pharma. These companies are very sensitive to announcements like these because they can be misinterpreted by the public/media. They'll be trying to find some alternative options and the details of the shortage will become evident from other sources eventually.

Why publish anything then ?

Because otherwise once shortages begin they'll be accused of a "cover-up"?

Well, we know that there is a disruption and that as far as the FDA knows it's just the one report so far.

In an administration that frequently gets involved in cover-ups, you can't fault the FDA for trying to disclose as much as they can without causing new problems.

Plus the press release goes on to detail many other areas of FDA's regulatory domain that are also helpful.

This this other comment (not mine) detailing these FDAs transparency re drug shortages:

https://news.ycombinator.com/item?id=22445961

So they can't say you they didn't tell you anything