The answer in 2020 is yes, states offering short-term plans will be offering longer short-term durations. The new mandate will make it so that short-term health insurance plans will last up to 364 days (some states up to 36 months). Some states will not be offer short-term plans in 2020 include California, Colorado, and Washington.
With fewer than 90 days left until the start of 2020, those buying 90 day short-term plans will not have to worry about renewing these policies. Instead, if they decide not to enroll in a long-term plan during open enrollment (November 1st- December 15th), they can start a new 364 day plan on January 1st instead.