IAR's are the worst thing that a closed grid could offer. Saving an IAR will save things that may not be the persons own creation. And when the person imports it to another grid or their standalone they become the "creator" and the "owner" of the items even if they were not the creator.
Grids of all kinds should NOT do this for their residents. If it's an open grid where you can connect your own region and you choose to save an IAR yourself on your own hosted region that's one thing. But the grid doing it for you would be them taking responsibility and that would be about the worst thing they could do for legal reasons in my opinion.
I guess there may be grids that have figured out how to do this for their residents and be proof positive that they are only backing up things actually created by that resident but I haven't heard of this if this is the case.