I'm going to wait a bit before getting excited. I know that the EPA is really cracking down on diesel tuners for defeating emissions devices and tunes that run *way* rich (rolling coal) but I haven't heard a similar level of enforcement outside of diesel market.
IMHO, the "For Offroad Use Only" loophole that allows us to get our hands on catless downpipes for our street cars should be closed. This will affect legitimate use in motorsports, but too many of us are running catless downpipes on our street cars for a little more sound or to save $100 over a catted downpipe. Mods like intakes, exhaust, and even turbos and tunes don't, necessarily, increase emissions. Catless downpipes, for sure, do.