HN is very industry specific. It would be like saying HN is disrupting forums. It's not. It has a very specific audience. Reddit has lots of above average and also has below average forums too. So, yes, the AL jobs board could become the board for all jobs, but then, it'd hardly be better than job boards now.

Seen another way, let's say the top talent is 10,000 individuals. There are way more positions and candidates than that out there. So if they became the Reddit of job boards, they'd have tens (dom)/hundreds (int'l) of millions of applicants in search of tens (dom)/hundreds (int'l) of millions of jobs. Neither the applicants nor jobs are going to become "great" just because they are on the Angellist board.