all of the SEC reporting and compliance obligations still apply. if they fail to file 10-Qs, they give the SEC a reason to revoke their registration. they also face other types of enforcement action. they still have to file all of the required 10-Qs -- a 10-K isn't enough.
if they become delinquent in their filing obligations they would be subject to suspension again and if they remained delinquent, their registration could be revoked. they could also file to become a non filer but they can't do that unless they are current.