IRENE KRISTAL, I, Plaintiff, v. MESOBLAST LIMITED, SILVIU ITESCU, and JOSH MUNTNER, Defendants., page-17

You're incorrect. They're not that a one man law firm and are focused on class actions.
These are their staff that appear under only one letter of their search directory https://www.glancylaw.com/our-team/?letter=L
Also it's not the only class action against MSB.

A class action is a huuuge headache. I don't know if you've ever been involved in a legal case, it is an enormous distraction, made worse by the fact that there is so much randomness with respect to outcomes. SI has major operational matters that he needs to deal with and this will take up a lot of his time and thought.
Whether or not they are successful or achieve an out of court settlement, there is something there to be concerned about.

Also, these posts re if you invest you take risk are missing the point. The issue is not that investments have risk. The issue is that the plaintiffs are claiming that management misled them. I don't know enough about the situation nor enough to guess the outcome, it's now up to lawyers and they often think differently to other people.