I think an apology before they've had a chance to review everything that occurred would be rather empty, don't you? "I'm sorry you're upset"?

I far prefer what they've stated they're going to do which is stop the activity they know about immediately, and to review how we got to this point.

If, on the off chance, the professor was being honest about ensuring they weren't wasting anyone's time, and ensuring no bad code made it into the kernel, then the situation becomes a bit more murky. They'd need to go through all of the associated emails both public and internal to validate that.

If on the other hand this is in fact a duck, I would expect them to both to issue a meaningful apology at that point, as well as lay out the steps they've taken to ensure it doesn't happen again (which they've indicated is their plan). And hopefully restore the trust of the OSS community.