I really hope that's an urban legend...... I can't think of any companies that actually have that as policy, I've heard of some stupid stuff but not this one....but all I know for sure is that the one pure IFT only company I've worked for definitely did NOT have that as a policy.
Anyways, yeah there's a ton of ambulance companies driving around town. They have lights and sirens and EMT's and say some form of "Ambulance" on them....but yeah, are pretty much dressed up gurney vans doing hospital discharges to SNF's, Dialysis transports, etc etc. Only 5 out of the dozens (or more) private companies in the County do any 911 response. I do know every McCormick rig has an AED, I'm pretty sure the same for Care, but not sure on AMR or Schaefer, all the rest of the AmbuMedLifeCoastStarResponseRescueOne don't actually do any sort of emergency response or transport (at least at the BLS level)
To the best of my knowledge, AMR has AEDs on BLS trucks.