In their app the new owner will not have access to the flight logs of flights you have flown unless you give them your log in details and they logged as you and then downloaded from DJI any logs you had synced.
Even when I have been given 'app logs' (via email) and put them on MY PHONE using MY login I can not view those logs in MY app. However I could use the likes of CsvView but that's neither here nor there.
If the
Air 2's behaves in the same way as the Mavic Mini and
Mini 2, the DAT logs on the drone are encrypted, unreadable, 'unremovable' and useless to anyone bar DJI.
However it might be possible to cause the drone to over write the DATs on the drone with largely unless 'junk' by switching JUST the drone on INDOORS (so no GPS) and leaving it sat, switched on, doing nothing until the battery is near exhausted. Repeat that a few times until the 'wiping logs' are the only logs visible in the Assistant 2 software on a computer. I doubt it's worth the hassle. If you try that I would suggest directing the output of a fan over the drone whilst it is sat, switched on, 'doing nothing', so that the draught cools the drone. But 'wiping' those logs might look suspicious if the new owner has a look at those logs themselves.
The only other things that they WILL be able to see that gives a partial indication of your usage of the drone are
1) the number in the names of photos and videos but you can reset that and its 'value' is limited by 'where' DJI set the counter reset i.e. does it count 99 +1 as 0 or 100 ......or 999 +1 as 0 or 1000.
2) similarly the number in the name of the DAT files. I think it is likely that DJI reset the count at 99 +1. Personally I think that is a shame and would MUCH prefer the reset that is used in the Phantom 3's i.e. possibly 999 +1 or 9999 + 1, my highest P3 DAT is in the 800's.