That may be more true in a super crowded and hot area, like AI now where reputable profs get dozens of PhD applicants per position, who all have already published relevant works in the field at top venues during their masters.

In more chill fields where the waters are relatively calm, this may be less of an issue.

But let's also consider the fact that Hassabis did his undergrad at the University of Cambridge, likely with excellent results. He wasn't just some random programmer.