I am adjacently knowledgeable on this subject and will try to answer it to the best of my ability.

First things first, addressing the source in the Wikipedia articles about the Seven Years' War French force size, I don't think that this estimate should be held to the same degree as the Grande Armée in Russia. The book cited is James C. Riley's The Seven Years War and the Old Regime in France: The Economic and Financial Toll. Looking at the book itself, Riley's analysis concludes that the total number of French land and naval forces were 650,000 to 700,000 at any given time during the war, with a yearly replacement of around 50,000 during active hostilities, to a total that is about a million men. Riley includes in this force the regular army, militia units, coast guard, watch companies, and all navy personnel, particularly from the merchant marine. In essence, Riley is using this figure to attempt to encompass every person that was mobilized into the military in any significant fashion by France during the Seven Years' War.

Total force numbers of the French army during the 1812 campaign are hard to settle on, and much scholarship has been written on it in the 200 years since. Estimates generally figure around 450,000 to 600,000 men in Napoleon's army when he entered Russia. If we accept the total number to be roughly in this area, then that means that this single campaign had nearly the whole population of the entire French armed forces at any point in the Seven Years' War. This number does not include troops deployed to Iberia or the French holdings in Germany and Italy, along with any French units in the homeland or naval assets.

Now, these specific units were diverse and multinational, drawn out of the pan-Central European power structure that Napoleon had constructed. Nonetheless, it represented significant forces under French control. You're correct in pointing out that this mass mobilization policy began before Napoleon's ascension, back in the 1790s, and perhap eclipsed Napoleon's own armed forces. The oft-quote levee en masse describes the process of conscription and volunteers that had been ebbing and flowing for an entire generation, since the revolutionaries had ideologically declared war on the monarchies of an entire continent. This truly represented a break from past army sizes composed primarily of regular troops and ad-hoc units of militia. Where the French army of the Seven Years' War comprised a few hundred thousand professional forces and militia units, the desperate forces that the French revolutionaries pulled together were primarily able bodied citizens across social and economic strata. These troops were totally green and completely disconnected from the established military tradition of the former French monarchy. It is very hard to reckon exactly how many people were conscripted, and how many actually made it into the French army, and how many actually saw combat. Even the roughest of guesses, however, will conclude that many hundreds of thousands of people served, with perhaps a million or more under arms at once. This force was altogether less well trained and more massive than anything wielded by its monarchical foes.

Napoleon's armies represented, in essence, a maturation of this conscription policy. His forces were not necessarily much larger, but they were certainly much better trained and honed by conflict. A recent book titled Winning Wars: The Enduring Nature and Changing Character of Victory from Antiquity to the 21st Century provides some precise sourcework; from 1798-1815 roughly 2,700,000 French men were conscripted under their conscription law at the time, and of that number 2,000,000 were actually incorporated into the army. Napoleon established a core of hardened troops, which by 1805 included a large portion of men that had seen prior combat, with the rest having ample time to train and integrate with their experienced comrades. Far from the desperate citizens of 1793-1794, Napoleon's army was composed of numerous trained army units, led by a group of well experienced meritocratic officers, who leveraged mass engagement tactics honed over the past decade of conflict to bring the full force of French manpower to its maximum effectiveness in battle. Napoleon did not perhaps command more forces than his predecessors, but he commanded troops with experience, and he showcased the force-multiplier that good training offers when he came as close as he did to carving out a French empire in Europe over a decade of war.