All coaches built for service work post May 2005 have to be PSVAR compliant (even prior to 2020), hence why from the 55 plate Profiles onwards all new coaches within Stagecoach had lifts, it's the same reason they stopped buying Skyliners because at the time there wasn't a PSVAR complaint variant. I don't think pointing out the illegal use of non-PSVAR compliant coaches is being critical as that would imply it's a matter of opinion, when it's not, it's a clear as day fact.
I'll be interesting to see how this plays out going forward, hopefully the appropriate authorities can be brought on to the case. I'd expect far better from a large firm like Flixbus.