To the best of my knowledge, Progresso lentil soup is appropriate for P1 and beyond (I've had it myself on P1).
Reduced fat sour cream is all right. It counts against your two cups of dairy for the day.
Tomato paste and tomato soup are fine. However, most processed tomato soups include sugar or other non-SB appropriate add-ons. I know the SB cookbooks have several recipes for tomato soup, all marked as appropriate for P1. I eat these tomato soups weekly without problems.
Yes, the food lists have changed. I believe most, if not all, of the updates are posted in the forum.
The tree that bears the fruit
is not the one that is planted.
- W.S. Merwin