According to the USCIS update on 06/17/2019:
"USCIS will implement a national strategy to decrease differences in processing times based on location for Form N-400, Application for Naturalization, and Form I-485, Application to Register Permanent Residence or Adjust Status.
Since the end of 2015, we have experienced an increase in processing times due to higher than expected volumes received during fiscal years (FY) 2016 and 2017 that did not decrease as originally projected. FY 2017 receipts were up 15.6% from FY 2016, and FY 2016 receipts were up 25.5% from FY 2015. The increased filing volumes did not affect our field offices equally, which resulted in some disparity in the processing times among field offices.
As we shift caseloads between field offices to decrease processing times, we may schedule applicants to appear for an interview at a field office outside of their normal jurisdiction. Applicants may receive an interview appointment notice or other types of notices (such as a Request for Evidence) from a field office outside of their normal jurisdiction. However, these caseload changes will not affect where applicants attend their biometrics appointments. We will still direct them to the nearest application support center. Applicants should follow the instructions on any notices they receive from USCIS.
USCIS remains committed to adjudicating applications, petitions, and requests for immigration benefits as effectively and efficiently as possible in accordance with all applicable laws, policies, and regulations while securing the integrity of the immigration system."