This might be a little too nitpicky but it doesn't get wiped. It's simply no longer associated with that object because it's considered a different object. It's still a huge, glaring issue, obviously, but all the data is still there.

In this particular case, the "object" was identified as one type of object and so all of the data related to that was classified as "car" info, for example, and then, when it's reclassified, that additional data starts recording to the "bike" info bucket. The software should have been keeping track of certain data regardless of that classification but it's only seeing the latest bucket of data. If the tracking history got wiped, we wouldn't have the data to look back on to see how this was all happening.