Excalidraw.app doesn't collect any user data. It uses Google Drive API to authorize user and get access to documents selected by user, but any of this data don't ever leave user's browser.
Excalidraw.app is browser-only web app and doesn't have any remote data storage (e.g. database).
Excalidraw.app's use of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements.