Brownells is saying differently:
https://www.brownells.com/the-trigger-times/guns--gear/tech-info/everything-you-need-to-know-about-selecting-the-right-suppressor/
CT, PA, TN, MS disagree
Open States (27) — No NFA Process Required
Alabama, Arizona, Arkansas, Florida, Idaho, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Minnesota, Missouri, Nebraska, New Hampshire, New Mexico, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, West Virginia, and Wyoming.
In these states, eligible customers can generally purchase a suppressor through the standard firearm transfer process, including applicable background checks and eligibility requirements, without completing an NFA Form 4.
NFA states: Alaska, Colorado, Connecticut, Georgia, Michigan, Mississippi, Montana, Nevada, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Washington, and Wisconsin.