There is nothing wrong with getting a plain vanilla job after freshman year. He will be a much stronger candidate for research next year, and developing the soft skills (dealing with angry parents if he’s a counselor at a day camp; dealing with hostile customers if he’s working at a diner) will serve him well.
If he has solid office type skills, he can make his own internship at a local non-profit (hospital, museum, advocacy organization, aquarium, bird sanctuary,) or political campaign (which ought to be heating up just as his last exam ends). He may start out doing traditional “bottom of the food chain” work on a campaign, but a math major will be able to interpret polling data (which many people- even experienced political types cannot) and do high value work doing segmentation and targeting.
And a final note- kids switch/drop out of already established campus research roles frequently. (they get a better offer, decide they want to go home instead of staying on campus, etc.) Your son should follow up with his professors up until the end of the semester… things open up suddenly and those jobs go to the kid who happens to be standing there. One of my kids got one of those…
Good luck.