I don't see why not. I see former rental and corporate fleet vehicles that have been CPO for sale all the time. I don't see why commercial would be any different. In fact, sometimes maybe that's the only way dealers can sell these types of units. Care to share why you are asking?
I've had a nightmare of a time with my 2011 CPO Limited Explorer, I've owned it 42 days and it has been in the shop 24 of those days. All sorts of stupid issues that should have been fixed before the thing was even certified and sold, like wheel bearings (3 of the 4 wheels now), A pillar noise, rust on hood, tires fraying at the wear indicators, 110v outlet missing with exposed metal prongs delivering 110v still (shock hazard bigtime for kids in the rear seat), rear brakes sticking on, sunroof shade won't close all the way, radio reception was non existent due to faulty antenna wire, brake lights looked like cop car lights and flashed constantly, and I'm sure I'm forgetting something else, but I'm beginning to forget about all the issues I'm having. It's almost easier to say what is working well (Engine is fine, transmission seems great, I'm averaging 23MPG which is lovely).
I ran a carfax on it just to see what's up and found it had 3 previous owners, the first one commercial for 3 years. I was led to believe by the sales guy that CPO Fords are 1 owner no accident vehicles, but after calling around to a couple of other dealerships I've been getting mixed information. The most recent thing I've heard is that Ford only looks at mileage and age of the vehicle, no matter how many owners or accidents.
After over 2 weeks in the shop I respectfully requested they sell me a different car or give me a refund, and I was immediately dismissed and was never given the time of day again by my dealership. They started refusing to take my calls, stopped responding to emails asking if the vehicle would be fixed, etc. I spent a great deal of time on the phone with Paul at Ford Corporate after Crystal on here got me in touch with him. He was helpful in lighting a fire under the service guys but at this point I don't need service, I need a quality vehicle like the one I was "sold" by the sales guy, not what I actually received.
I have 52,000 miles on it and I have the CPO warranty until 63,000 and extended warranty until 125,000, but I'm not sure it will last that long at this rate. And I can't be without my vehicle 2.5 weeks of every month while I own the thing. The dealer keeps reminding me that everything is covered and they will fix everything, but that is beside the point. None of these things should have happened in the first place, they should have never sold this vehicle.
Ford Corporate threw in free of charge the 45,000 maintenance plan, but if they never did any of the maintenance or re-conditioning items before the certified the thing, why would I believe they'd take care of the thing now?
The dealer also put new tires on it now, to try to keep me from suing them most likely. I'm just at the end of my rope and wanted to see what's what on the CPO process and if they certified my commercial vehicle when they shouldn't, but it sounds like they only look at miles and age.
I guess I've learned to never buy a used car in the rain so you can hear noises and see paint issues, that's for sure. I'll also never buy a used car without several test drives in different types of weather. I'll also never visit this dealership ever again and will preach it from high atop the mountains to avoid them like the plague. Paul at Corporate basically is powerless at this point, and when I mentioned contacting my lawyer he said I'd be completely within my rights to do that and it's totally a dealership issue at this point. I just don't want to waste thousands of dollars and months of time to fix something that A) Should have never happened (on either end, I should have never purchased the thing and they should have never sold it like this), and B) could be easily resolved by giving me a different certified (actually certified) Explorer (not commercial etc.)
Buyer beware, and don't believe the dealer has your interest or well-being in mind at all. A "CPO" vehicle means they ticked some boxes on a piece of paper and put the letters CPO in front of the listing. I fell for it.