My reading is that the examiner thought "advanced custom fields" was too generic. WPE had until Oct. 19 to file a response or ask for an extension, and they ask

My reading is that the examiner thought "advanced custom fields" was too generic. WPE had until Oct. 19 to file a response or ask for an extension, and they asked for an extension on Oct. 4. For "ACF" however, the examiner didn't see a problem and it has been published in the Federal Register. It will be registered if no one files an opposition during the publication period. You don't need to have a registered trademark to sue for trademark infringement; registration does make it easier to assert your trademark and can increase damage in a court case.