> Respond how?

By destandardising sizes. It isn't that hard to standardise if an industry thinks it'll help them; the article suggests there is already a relevant standards body. These companies are probably doing it for a reason. My guess would be maybe someone doesn't want to be an XXL 18 at J Crew so they can go to Reformation where they are more of a Regular 14.

> Signal what?

Age, health and status for women. Group membership too although that is generally to a lesser extent.