The details of what our carrier partners can see is in the table at the bottom of our privacy summary: https://www.cape.co/privacy-summary. We add noise to their data by doing things like rotating your IMSI daily and spreading traffic among multiple carrier partners. If the data is messy enough and not associated with your personal information, there should be less monetary incentive for the carrier to try to piece it together when they have an abundance of clean data with stable identifiers and verified personal information.
Additionally, with disappearing call logs, it's about reducing surface area. Fewer logs in less places.