I doubt that any cleaning manufacturer will raise eyebrows to the vehicle manufacturers to alter their warranties - so you'll have the choice of PTO and no vehicle warranty, or slide in.
As far as the original topic
Personally - I don't think we have much to worry about other than paying a bit more for the engines and or having our options limited.
Small engines is what Briggs, Kohler, Kubota, etc do. Maybe the likes of Hyundai and Nissan exit the small commercial engine market - but the small engine only companies will still be here. We'll pay more for the products.
If they regulate the new/revised EPA cert's like they do CARB/EPA certs for CNG application (which I doubt because the idea there is to stall development) $100K per cert, $10k/yr per cert registartion - we'll see less options and the TM manufacturers will have to redesign around available powerplants, again, we'll pay for that.
But to worry that there soon won't be small gas engines to power TM's I don't believe is a worry. The TM manufacturers will have to redesign to use what is available, maybe an entry level TM is no longer an optiononly mid and larger units, but we'll still be rug sucking with them in the decade to come.
