Unfortunately, I was not able to fully recover the information.
Skatter saves the name of the Scattered Objects specifically for cases like yours, when the link to the SketchUp object is broken, to make it easier to pick the right object. But it looks like they were not saved in your file, I was not able to find why.
It seems that your Skatter v2 were originally converted from Skatter v1 setups. Maybe that’s why the names were not saved, I’ll dig deeper.
The somewhat good news is that the v1 data is still present in the file (it is kept as a hidden backup in case the conversion to v2 goes wrong). So I was able to pull out the following. Keep in mind that this is old outdated data, it looks like that the Scattered Objects were changed after the conversion to v2, as the number of Scattered Objects don’t match between the v2 compositions and their respective v1 backups.
Arbres vue aérienne:
There is also “Arbres projet”, but this one doesn’t have a v1 backup.
I hope this can help!