False. Apps don't have access to cellid information unless they also have location permissions, in which case they can just request your location directly.
>the free apps you install and use collect your precise location with timestamp [...]
This is alarmist and contradictory given that the author admits a few paragraphs up that the "location shared was not very precise". It might be possible for the app to request precise location via location services, but the app doesn't request such permissions (at least on android, you can't check for requested permissions on iOS without installing the app and running it), so such apps are most definitely limited to "not very precise" locations.
>At the same time, there is so much data in the requests that I'd expect ad exchanges to find some loophole ID that would allow cross-app tracking without the need for IDFA.
At least in theory they're not supposed to do that, but it'd be hard to enforce.
"If a user resets the Advertising Identifier, then You agree not to combine, correlate, link or otherwise associate, either directly or indirectly, the prior Advertising Identifier and any derived information with the reset Advertising Identifier. "
https://developer.apple.com/support/terms/apple-developer-pr...