I don’t think it’s ready for a comeback, but maybe someday? People have given other examples of names with a similar vibe (Mabel, [name_f]Vera[/name_f], etc.) but I think [name_f]Gladys[/name_f] has a much clunkier sound. I can’t say that I see it moving from “grandma” to “grandma but also fashionable on a baby” anytime in the next 10 years.