This is still a significant win.
This doesn’t mean state legal machine guns though. State laws will still exist so you’d still do Nebraska time if you had one.
What it does mean is if Biden passes an AWB, local police will not escalate it to the ATF if you’re caught with one. This is actually where the majority of federal gun charges originate from. If the NSP caught you with a non federally compliant firearm that didn’t violate a Nebraska law, nothing happens now. Without it, the NSP would arrest you and hand you off to the ATF.