In the most definitive statement yet that Keystone College might fold, its accreditor has alerted the public that closure may be imminent. The Middle States Commission on Higher Education posted on its website Wednesday a message titled “Statement on Keystone College Closure” to correct “misleading information” from the college about its future and to leave no doubt that its outlook is dire. In March, the financially struggling, 156-year-old college scrapped a plan to have an outside group take over ownership of the college straddling Factoryville in Wyoming County and La Plume in Lackawanna County. Keystone College also is preparing to hold an annual Commencement graduation on May 18 and to hold summer activities on campus.