Like I said, they automatically investigate to see if there is a...

Like I said, they automatically investigate to see if there is a case and if they can get a shareholder to be a plaintiff in the case. It's a law firm, they make lots of money from these so if there's a chance they can do a class action they will see if there is a basis for one. 99% of the time there isn't, hence why they're rarely even reported on. Unless they actually say they'll launch a class action (rather than simply investigate), there's no reason to suspect there will actually be one.

Research reports suggesting a company misled investors is certainly good reason for a class action, and would be something a law firm would investigate to see if there is a basis for a class action. Of course, they'd quickly find that this one is rubbish and would subsequently conclude investigations and not engage in a class action.