sure why not .. based on the little you have told us ...

why not find somewhere to plant them in the ground.. if they are still small ...

the real question is... will they be quality peas ... as second generation seedlings...

ken

If you don't thin them you'll end up with a lot of weak plants searching for light and nutrients, You know how many you had in the pot last year so keep it the same if they did well. You may want to keep a few in separate pots in case some of the ones you leave don't do well or get attacked by slugs or other pests