Had a look at syns online, and can't find anything from the chilled section. I'd be a bit suprised if it were free, as every other ready made soup does have syns, even 'skinny' ones!
Have you got nutrition info?
I'm very sceptical because so far you've never been allowed to use Free Foods in soups - and even if we do count onion as Free that still works out as 3½ Syns per pot. If you dont include the free food it's 1 syn per 20 calories so 16 syns a pot.
Who knows, maybe they'll change the rules again? But at the moment I would definitely syn it or just make my own.