I wasn't necessarily assuming that Perseverance would be functional to hand the samples over; rather, I thought it might intentionally store the onboard samples in a fashion where another rover could easily grab them without direct intervention from Perseverance itself. Something like a tray or rack of tubes with each sample having exposed grips.

The comments made by others suggest that Perseverance does have onboard samples like this, and the dropped ones are secondary (in case something happens to Perseverance to destroy all its onboard samples -- I don't know, catastrophic damage to its radioisotope power generator? Or perhaps more realistically, it gets stuck in a sandy area which is too dangerous for other rovers to approach without also getting stuck), which makes more sense.