This is a huge decision by SCOTUS that reverses nearly 40 years of precedence; bad precedence I might add. There are many other implications than just how the ATF acts. It will rein in all sort of governmental agencies that have been creating laws, without having the authority to do so.
It's just too bad it's taken 40 years to correct these unconstitutional actions by Federal agencies.

This is a huge decision by SCOTUS that reverses nearly 40 years of precedence; bad precedence I might add. There are many other implications than just how the ATF acts. It will rein in all sort of governmental agencies that have been creating laws, without having the authority to do so.

No, SCOTUS cannot issue orders to the ATF but they can absolutely strip them of Chevron Deference powers and restore the Rule of Leniety.

Chevron Deference is a past SCOTUS ruling that basically says where Congressional legislation is vague in definition or instruction then deference is granted to federal agencies to freely interpret as they will when it comes to rule making.

Whereas the Rule of Leniety says that where there is a grey area then all due deference must go to the citizen, especially when questions of constitutional rights or criminal penalty are involved.

The case in question here doesn't even involve the ATF at all. Instead the EPA and Corps of Engineers got a nine/ought slap down in a Waters of the United States case over a wetlands ruling the EPA had made. They prosecuted a couple for dumping gravel in a mud hole on their property.

Two things came out of it, the first is that "wetlands" governed under the legislation must be actually attached to navigable waters and second that the EPA does not have rule making power outside of what is specifically in the congressional legislation. If grey area they don't have the authority.

This most obviously can be applied to the ATF in the current brace rule over reach or the recently overturned bumpstock ban.

It almost certainly will have wide reaching effect on the multiplicity of unelected alphabet agencies making up rules out of whole cloth.

in todays world within the usa you can count on government agencies overreaching their authority regularly. state agencies also. most people do not have the funds to hold them accountable..