The causes of the Revolution are pretty well known: essentially, a series of taxes ( the Stamp Act and the Townsend Act) levied on the Colonies to pay for their share of the cost of the Seven Years' War, ( sometimes also called The French and Indian War) was met with protests almost immediately after they were imposed, in 1763. Those protests and attacks on tax collectors were met with various responses, some conciliatory, some abusive. The situation grew worse after the Boston Tea Party of Boston in 1773, which resulted in the retaliation of the Coercive Acts. As Lord North is often quoted:

The Americans have tarred and feathered your subjects, plundered your merchants, burnt your ships, denied all obedience to your laws and authority; yet so clement and so long forbearing has our conduct been that it is incumbent on us now to take a different course. Whatever may be the consequences, we must risk something; if we do not, all is over.

The Coercive Acts imposed several things. They closed the entire Port of Boston , until the damages from the destroyed Tea were paid, thus holding the whole town responsible. They took away the Massachusetts charter, removed powers of local government and gave them to the Massachusetts governor, who was a royal appointee. They gave the governor the power to send any defendant accused of a crime to England for trial if he did not think they could get a fair trial in Massachusetts ( for example, a soldier who had shot a colonist).

One applied to all the Colonies, the Quartering Act, which allowed a governor to assign quarters for soldiers. But the real effect of the Acts fell on Massachusetts, giving the governor, General Thomas Gage, great powers, unchecked by local authorities. Gage was a military man, had been governor before. He had already moved two regiments of soldiers to Boston in 1770, which had resulted in the Boston Massacre ( though that not under his watch). In other words, he had been given power, was happy to show force to deal with protests, and he did. In 1774 he brought in more troops from garrisons in New York and other northern colonies, brought in warships, and in Sept. 1774 he sent 200 soldiers to move the gunpowder from the magazine in Somerville. This was the " King's powder", under his control ( Kopel states it was partially private citizens'- but those stores had been earlier removed), and moving it to Boston for safekeeping was not unwise. But it galvanized the population into grabbing their guns (the Powder Alarm) which resulted in the Battle of Bunker Hill and an armed insurrection which grew into the Revolution.

Kopel makes much of Gage and his "disarming" efforts in Massachusetts. Certainly, the Powder Alarm set off Bunker Hill...but there were already people totally ready for insurrection, before that: that was just a spark. The colonists were already furious about the imposed taxes, removal of local authority and British soldiers everywhere. Kopel cannot cite any other specific disarming actions taken by other governors in other Colonies: he does mention the NC governor banning independent militias, but admits the proclamation had little effect. And indeed, in other Colonies there was a local assembly that could contest the Governor, so it's hard to see how Gage could have been duplicated. Still, despite this Kopel's piece just simply begins to assume the reverse; that, despite there being no confiscation elsewhere, fear of confiscation was everywhere, and that this fear drove the revolt. Yet where is the confiscation of guns as a specific significant complaint? When Virginian Thomas Jefferson drafted the Declaration of Independence, most of the grievances he listed were contained in the Stamp Act, Townsend Act, and the Coercive Acts. There is nothing in it about King George taking away people's guns. But even in this, Kopel has to see something about arms control

The Declaration listed the tyrannical acts of King George III, including his methods for carrying out gun control: “He has plundered our seas, ravaged our Coasts, burnt our Towns, and destroyed the Lives of our people".

See anything in that "plundered" line about guns? To apply a bit of Occam's Razor, here: we have documented causes for the Revolution that explain it quite well, and these causes and the resulting protests long antedate Gage's actions. And Gage's actions were confined to Massachusetts. We do not need to explain the Revolution by imagining other causes, if there's no good evidence for them. But then, Kopel is not so much interested in really doing history than simply rowing through some assembled statements to his desired objects, like:

The reaction against the 1774 import ban for firearms and gunpowder (via a discretionary licensing law) indicates that import restrictions are unconstitutional if their purpose is to make it more difficult for Americans to possess guns. The federal Gun Control Act of 1968 prohibits the import of any firearm that is not deemed “sporting” by federal regulators. That import ban seems difficult to justify based on the historical record of 1774-76.

So, because Thomas Gage secured government munitions from possible use by insurrectionists in 1774, the government now shouldn't ban imported military weapons. I am myself a gun owner, hunter, and have my own biases...but that's just jaw dropping.