I'm certainly no legal expert or authority, so take this for what's it worth. I am however both an FFL (type 7-manufacture) and an SOT (can manufacture suppressors / machine guns, etc.) When this law got signed by the governor I specifically asked the ATF about manufacturing both guns and suppressors. The response from the agent was a verbal one and doesn't really carry much weight but he said: "Anyone trying to make Utah only guns or suppressors will have ATF agents all over them and a lawsuit to deal with." He said this was especially true of NFA items.
In a way, everyone has always been able to make suppressors. It's not that hard. You could even use them without consequence (albeit illegally) as long as the ATF never found out (of course I'm not advocating this)... The only difference now, is that the court case will be more interesting if you are caught at this point.