So, it's basically a stab in the back on the part of the Senior Officers? Lions led by sheep?
I'll say, knowing they had enough ammo kinda goes against the common myth exemplified by the classic and ironic "ready to the last brass button" meaning they were actually not prepared at all.
How prepared was the French army?
I was going to say something about how it depends how you look at it, but the truth is that the French army was miserably prepared for the 1870 war. It wasn't necessarily that they were a bad army, they had their flaws, but a war with Prussia, the best European army for fighting such a war, was the one where the French army would be at its worst fighting. It was very good fighting colonial wars and limited engagements like beating up on the Austrians, it was atrocious for fighting a modern industrial and total war against the Prussians. Organization was chaos, logistics were awful, mobilization terrible, European cavalry scouting wretched, communications awful, conscript forces horrifyingly bad (the garde mobile was essentially a paper force and almost worse than useless), intelligence poor (both for espionage and such but also for the officers too often...), military education backwards and poor (most French officers didn't get any additional military education after their academy years - which were in of themselves, not as good as the Prussian equivalents - while every German garrison had military discussion societies), planning non-existent (the French didn't even have an offensive plan for the war, all they had was a defensive plan), they didn't even have maps of the front, the idea was that officers
would buy roadmaps for the front. They were also dreadfully out-matched in regards to artillery, and no proto-machine gun of the mitrailleuse was going to match Prussian field artillery, no matter if the French had actually figured out how to use it or not. Tactical doctrine was also pretty awful, the French went for grouping their men into tight trenches to concentrate their firepower, and then these got blown up by the Prussian guns. They didn't even deploy their skirmishers as actual skirmishers, they kept them with the formations instead of putting them on the flank and skirmishing ahead, to add to the feu de bataillon. Officers were defensive and listless, they didn't even march to the sound of the guns of their comrades when they were under attack, preferring to stay in their fortifications. Metz is the largest army which simply sat there, but army after army in the initial phase of the campaign simply did not move when formations next to them were under attack.
The French army had been an army which had prided itself on aggression and the système D, using attack columns and initiative, just a few years before. It changed this to focus on defensive tactics after the results of the Austro-Prussian war came back, when Austrian formations, which had themselves moved to the French style attack columns and adopted French artillery tactics, had been brutally crushed by the Prussians, when their attack columns got shot to ribbons by Prussian needle rifle fire and artillery. In changing to this defensive army it seems to have picked up all of the negative aspects of an army focused on the defense, while maintaining precious few of those of its previous offensive spirit.
This all being said, we shouldn't undersell the French army in 1870. Battles like Gravelotte show them at their best, when the French army inflicted horrifying casualties on the Prussian forces attacking them. The French might have had all of the terrible organizational flaws previously discussed, and their troops might have lacked for discipline and often been drunks, but the French troops did subscribe to that système D: one example which
The Franco-Prussian War: The German Conquest of France 1870-1871 (great book by the way, it is where I base almost all of my responses to this thread on, if you don't have it I would recommend getting it and I could send my digital copy of it to you if you want) had presented was an inspection of French troops in Aix-la-Provence. Rifles and equipment were dirty, troops undisciplined, chorists could not sing, fencers could not fence, a high proportion of NCOs were in jail or had been demoted to privates for small crimes. But the troops
did do excellently at shooting, and to the French, that was proof that when it actually came down to fighting, they were the best. The French army, in tactical engagements, tended to fight well, it just was miserably bad operationally and strategically so that by the time the tactical engagements opened up, their fate was often sealed.
Does that make them prepared for the war? I'd say probably not. Just the ability to fight well tactically does not a war-winning army make.