Char B1s were notoriously expensive and complicated to build - something akin to 3-4 more expensive than say, an H35/R35 light tank, although I don't know the man hours comparison. Managing to equip the entire French army with them would be next to impossible from an industrial stand-point. Something grievous would have to be cut in order to manufacture so many of them: it isn't simply a question of letting loose the financial floodwaters of rearmament, massive industrial capacity increases would have to be diverted from somewhere else - with the only sector that might provide such huge increases in production being the Air Force - in order to achieve those production numbers. Even then, I highly doubt that it is possible. This would almost certainly worsen the French situation by making the army substantially more lopsided and ill-balanced.
As far as impact, some units, like the cavalry with their DLM and DLC armored divisions, are simply not very well suited for the B1's usage, as they need faster, lighter, more mobile vehicles, rather than the B1. The only significant upside is that French DCR tank divisions would be formed earlier, since their formation was delayed to attempt to enable all of their forces to be constituted of B1s, and such a massive amount of B1s would make that possible. Forming them earlier would be very useful since it would give additional time for training, organization, and doctrine to be worked out, which was a severe problem for French DCRs historically, as they had only been formed relatively late and had not had enough time to fully work up to full combat capacity. Correcting some of their problems like the lack of infantry is probably possible, and they might put in a more credible performance - but in the light of the general French situation, they probably will simply get overwhelmed in the tide of battle, like the 1re and 2e who simply ran out of fuel in their counter-marching and confused logistic situation, and promptly had to abandon and blow up their tanks. This is especially so if the rest of the army is underfunded and ill equipped due to such a massive focus on heavy tanks.