Since you don’t know how long they were outside I would still harden them off.

tj

Maybe....maybe not :-) It depends on your location and how long the plants have actually been outside. In my area, although nighttime temps are still not warm, there is no need to harden anything off. Everything is sold outside (except houseplants).

I’m zone 7 so like 50’s at night

I've never really had any big problems with vegetables sold that have been grown in large greenhouses, just avoid extremes.

It's helpful to understand what exactly "hardening off" is doing. The main threat to young, indoor-bred seedlings is sunlight. Such seedlings have poorly formed leaf waxes and cuticle and, as a result, the leaves will lose water fast, especially in direct intense sunlight, which is VASTLY brighter than most germination lamps. Limited exposure to sunlight will build those waxes and cuticle. That's "hardening". In this respect, "outdoors" doesn't mean much. If the plants were in an outdoor display, but shaded under a canopy, as most nurseries will do, that hardening largely hasn't happened, and you'd need to be especially careful to keep the unhardened seedlings well watered. Developing cold tolerance is another thing that hardening does, but that's mainly about reducing the amount of freeze-prone water in the leaves and building up carb reserves in them. If you're not looking at temperatures anywhere near freezing, building up some cold tolerance is less important, but plants stored outdoors have already done that.