It is certainly possible that Ashley was once a popular boy name. The point is that, contra the article, there is no evidence for this in the SSA data they have based their analysis on.

I think a lot of these cases would be hard to answer definitively just because we don't really have accurate data more than a century back. And the fact that lots of people will repeat the claim "Ashley used to be a boys name" can be equally well explained by the fact that parents had to say something when their sons asked why they gave them a girl name, and they didn't have the data either.

What is true is that people who named their sons Ashley or Dana or Lindsay, at the time, most likely did not perceive those names as feminine.