I can honestly say that no-one considered an expert ignored the pro tour. If they did then, by definition, they were not in any way expert. It simply was not reasonable to consider the amateur game the equal of the pro game until the latter half of the 1960s, so only for a short period was there any doubt. Maybe 3, maximum 4 years, i.e. a few years after Laver turned pro, and before Open tennis. And of course the doubt was clarified immediately Open tennis started - the pros were better.