i can tell you one thing they don't record: [ & this suggests they do not rtrack what is read on the device either]
We have mislaid our kindle ( e-ink) and in desperation I phoned amazon, after ransacking the house for an hour.
I'd gone to my apps and devices -> devices and it was not listed so I was sure it had been lost/stolen and deregistered. [ turns out you have to check a different devices screen - that one is only for devices that use the app store - so it is still registered to me]
So, having established that it was
not stolen , I asked it they could tell me when it was last on-line - to help us track where it may have been last used, and the lady said they do not store that info, for customer privacy reasons.
she did helpfully deactivate it ( and explained the difference between de-register and de-activate). if we find it, and contact them again. they will re-activate it, but no one else can register it to a different account.
and she gave me the S/N[ which actually is on the device screens if you go content and devices -> books -> devices ] though I thin the Square Trade insurance does not cover forgetfulness !
i blame the wife