NVIDIA issued a statement to clarify the matter and claims the data collection is exclusively for crash and bug reports, as well as system information needed to optimize drivers and GeForce Experience settings.
Furthermore, the chip designer claims the telemetry services were part of the GeForce Experience since version 1.0. The only change is that GeForce Experience 3.0 made the error reporting and collecting real-time:
GeForce Experience collects data to improve the application experience; this includes crash and bug reports as well as system information needed to deliver the correct drivers and optimal settings. NVIDIA does not share any personally identifiable information collected by GeForce Experience outside the company. NVIDIA may share aggregate-level data with select partners, but does not share user-level data. The nature of the information collected has remained consistent since the introduction of GeForce Experience 1.0. The change with GeForce Experience 3.0 is that this error reporting and data collection is now being done in real-time.
All of this information is included in the EULA and the FAQ posted on GeForce.com:
Check our previous article for details on how to disable these services if you're concerned about your privacy.