The 403s are probably just bot blocking and not a crawl policy, since a 4xx on robots.txt normally means no rules were found
I checked the WSJ file today and it looks pretty strict, it disallows everything by default and only allowlists a few agents, so counting only named blocks might undercount closed sites.
Small thing -- the text says 8 crawlers but the table has 9, and a sample size for the news numbers would be nice to see