With "recurrent nevus phenomenon" could a previously benign mole now appear dysplastic if pathologist not aware of previous biopsy or laser ablation?

Yes. Hx is important: When a benign nevus grows back after biopsy, and is re-biopsied or excised, it may now show features that closely mimic a dysplastic nevus or even melanoma under the microscope. This melanoma-like pattern is called "recurrent nevus phenomenon." A pathologist might accidentally misdiagnose a benign, recurrent nevus as a DN or melanoma, if they don't know (or suspect) it was previously treated.