The linked article says: "However, says Arm, it appeared from subsequent press reports that Qualcomm may not have destroyed the core designs and still intended

The linked article says: "However, says Arm, it appeared from subsequent press reports that Qualcomm may not have destroyed the core designs and still intended to use the blueprints and technology it acquired with Nuvia" Obviously it's hard to know for sure - it could even be an Anthony Levandowski type situation, where an ambitious employee passes off an unauthorised personal copy as their own work without Qualcomm realising.