One argument that I have observed is that there was generally greater pro-British sentiments among colonists in northern colonial capitals (keeping in mind that a Canadian national identity did not yet exist) than in their southern counterparts. Michael Eamon notes in Imprinting Britain; Newspapers, Sociability, and the Shaping of British North America that printing presses in Halifax and Quebec City were far more pro-British than their equivalents further south. It is very li

The more loyaslist writings further north implies that coilonial elites were already pro-British, and there is a fair argument that their printing presses helped influence a more pro-British attitude among other colonists. However, why were these elites more favorable to Britain than their counterparts further south? I have seen some conflicting theories, but the ones that I am most familiar with are:

• Colonies like in Newfoundland and Nova Scotia were largely isolated from political upheavals along the Thirteen Colonies. Economic concerns did not affect them as much.
• Ordinary colonists were frightened by the American excursions into what is now New Brunswick and Nova Scotia, as the borders were not the most clearly demarcated.
• The Quebec Act of 1774 pacified colonists by allowing for a co-existence of French and British laws/cultural practices. Why would people revolt if they had no grievances

I am definitely missing some of the other reasons, as my experience with British Imperialism is more extensive outside of the Americas, but hopefully this is a satisfactory start.

Sources

Dallison, Robert L. Hope Restored. Fredericton, CA: Goose Lane Editions, 2003.
Dunsmore, Kate. “On the Edge of the American Revolution: The Nova Scotia Gazette in 1775.”
American Journalism 37, no. 4 (2020): 522–45.
Eamon, Michael. Imprinting Britain; Newspapers, Sociability, and the Shaping of British North
America. Montreal and Kingston: McGill-Queen’s University Press, 2015.
Kerr, W. B. “Newfoundland in the Period before the American Revolution.” The Pennsylvania
Magazine of History and Biography 65, no. 1 (1941): 56–78.

Just to add to what u/Kerokawa has said, and they are pretty much on the money, it is worth expanding a bit on the situation in Canada during the period of the American Revolution. I have answered a similar question before, and here is an extract:

Canada in the 1770s

The country of Canada, as we know it today, did not exist when the first shots of the American Revolution were fired near Lexington in 1775. Britain had received the colony of Nova Scotia, as well as claims to Newfoundland, from France following the War of the Spanish Succession in 1713. Furthermore, France ceded its larger and more populous colony, New France, to Britain following the conclusion of the Seven Years War in 1763.

Unique among the other British colonies in North America, Quebec was primarily French-speaking and Catholic. According to Desmond Morton, there were 60,000 people living in New France when in 1760 - shortly before it was formally ceded to Britain. Although the British hoped that sustained settlement and the imposition of British law would quickly remake the demographics of New France (now known as Quebec) to something more aligned with the rest of their colonies, that was soon proven to be unrealistic. Instead, the Quebec Act (1774) recognized the rights of the French-speaking canadiens to retain their language, French civil law, and the Catholic church - a not insignificant concession when you consider that Catholicism was literally illegal in Britain. The Quebec Act, remembered as one of the "Intolerable Acts" if I remember my American history, also extended Quebec's territory southwest into the Ohio River valley. While the Quebecois may not have been enthusiastic members of the British Empire, with their rights and privileges guaranteed they were essentially content.

As you may recall, the American colonists did try to rally Quebec to the cause of revolution in 1775-1776 during their failed invasion of the province. While the population of Quebec was not very keen to support the British - despite the urging of the Catholic clergy, who encouraged their parishes to support the Crown - they were equally unwilling to aid Continental Army general Richard Montgomery and his men. After the siege of Quebec dissipated early in 1776, the Americans returned home and abandoned their dreams of winning over the stubborn Quebecois. Meanwhile, any grumblings in favour of the colonial cause in Nova Scotia were quickly suppressed by the arrival of a British fleet in Halifax. With Nova Scotia thusly fortified and with the French-speaking populace largely pacified, Britain was safe to focus its attention on trying to hold on to its more rebellious colonies to the south.

I always recommend A Short History of Canada by Desmond Morton for an introductory text on Canadian history, or similarly the Penguin History of Canada by Robert Bothwell. Both are serviceable surveys of Canadian history, although they skew far more towards the political and economic history of the country rather than a social or cultural lens.