A class action suit requires a complaint. The complaint proposed by that poster would not result in a certified CA. It wouldn't even spark a complaint.
There have been hundreds of public biotechs and have been many thousands of instances where a company has said they planned to do a trial. And there have been many, many thousands of complaints, CA solicitations, and suits. If you can find a CA suit where the complaint was a trial was said to be planned but wasn't (either planned or performed), you'll prove me wrong. But you won't. Even in this age of Google. You won't even find such a complaint.