You just want to pay attention as they grow in that the corners don't get ingrown. That would be the only reason to be concerned. Often it's not that they are too short as much as you may have left a bur of uncut nail in the corner, and as the nail grows, this little spear is pushed into the skin and causes pain and even infection. Just gently pry the corners free of the skin periodically as the nails grow in to make sure the nail is free of the skin.
Hi and welcome. yes. Your toe nail will grow back. That's what they do and why you had to cut them in the first place . . . they grow. good luck