There's two things at play here. First, candidates who complain about the whiteboard interviews uniformly complain about it "not being a good representation of

There's two things at play here. First, candidates who complain about the whiteboard interviews uniformly complain about it "not being a good representation of how I can write code" which betrays a lack of understanding of the other skills besides writing code that these firms care about. People who understand more can connect the interview type to the other relevant attributes, so it's already clear who's more right. Second, yes, companies do a shitload of triangulation on recruiting performance including looking many years out.