If my I-485 Adjustment of Status Application is still pending, and my priority date is no longer current, will the USCIS still issue a biometrics appointment notice and/or a Request for Evidence (RFE)?

They may. The USCIS can still process the case but cannot approve it until the priority date is current. Therefore, you may receive Requests for Evidence or biometrics appointment notices. It is important to comply with these requests. Even though the case cannot be approved, it can be denied for failure to provide information or failure to show up for a biometrics appointment.