True! I typically wouldn't use vegetables with this roast, because the "gravy" is pre-made and flavoured by the condensed soup (which has the veggie flavours in it), but in general that's a great idea for roasting things, and YMMV.

When we roast turkeys in my family for Thanksgiving/Christmas, we use enormous ribs of celery in the bottom of the roasting bag in lieu of an actual roasting rack.