There is something significantly wrong with the folks planning to carry out this "protest" - but whatever that is seems to be left behind in the dust by some of the commenters.
While I generally think of the "open carry movement" as the attempt to normalize the lawful carry of properly holstered handguns, I understand the inclusion of long guns in the open carry effort to show that non-military and non-police can be both safe and non-threatening while exercising the right to bear arms.
The amount of "terror" expressed by opponents, based on what may happen, always astounds me because it fails to recognize the documented risks of causing deaths and blood to run in the streets by such things as the public use of automobiles and the public wearing of sports team-themed clothing.
Thank goodness I live in a region where a well-modulated "Well, I never!" is considered the height of approbation.
stay safe.