This looks like a few steps in a positive direction. Maybe ATF bureaucrats know how much patriots would like to just get rid of ATF, so in the hope of keeping their jobs they are making the agency more a friend than an enemy (or at least look that way). Just a thought.
The definition of sporting purpose does not need to be changed. What needs to change is that there should be NO sporting use language in any gun law. If this was not obvious before the Heller Decision, that decision clarified it. This kind of language is a dagger in the heart of the Second Amendment, and doing away with all of it should be a high priority. This of course can not be done by ATF, and would have to be done by Congress.
I would think that if removing the illegal burdens on owning suppressors can be undone other changes that could be made just as easy would be removing the illegal minimum length requirements, and perhaps changing the definition of machinegun to one that fires more than three (or maybe five) rounds with a single pull of the trigger, so the militia can have burst capability. And if a gun goes over that limit, the charge is a misdemeanor, like a speeding ticket for going a few miles over the limit.