Only the posting may be new. The ordinance, shown below, has been in effect since March 2013. The sign is probably deliberately misleading, or at least incomplete, in an attempt to keep those who do not know the law from carrying a gun.
Cornelius ordinance 93.10:
(A)***No person except duly authorized local, state or federal law enforcement officers, and duly authorized town employees or officers shall carry, possess or discharge any type of firearm, explosive device, air guns of any description (BB guns, paintball guns, pellet guns, and the like), or Bowie knife, dirk, dagger, slung shot, sling shot, leaded cane, switchblade knife, blackjack, metallic knuckles, razor, shurkin, stun gun or deadly weapon as defined in the North Carolina General Statutes within any park unless authorized by permit issued by the Director.* In accordance with state of G.S. Article 14, Chapter 14, Session Law 2011-268, carrying of handguns on or in town parks and recreation centers will have the following rights or restrictions.
******(1)***No person shall possess or carry any nonconcealed (open carry) handgun, gun, rifle, pistol or other firearm on or in any park or recreation center.
******(2)***Any person that possesses a valid State of North Carolina concealed handgun permit may carry a concealed handgun on or in a town park or recreation center, with the exception of Bailey Middle School Recreation Center and Football Field and J.V. Washam Elementary School Recreation Center and Football Field. A person carrying a concealed handgun on or in a town park or recreation center must abide by North Carolina state law governing concealed weapons.