It certainly isn't "well over 5 years since it was introduced" either. The minibus I drove on the A1 in 2009 certainly wasn't equipped with an electronic member of the green party.
It is over 5 years. The fleets have never been 100% equipped with this kit, and they still aren't (it's only on selected vehicles, generally the standard cars, minibuses and vans along with specialist vehicles aren't equipped), so the fact you drove a minibus once that didn't have it says nothing about the introduction date.