They managed 325 in about half a year, I think they can manage to get another 200 and repair the damaged ships at Le Havre at the same time.
Have they actually got the materials for building those other 200 in stock? If that construction wasn't pre-planned then its far more likely that building the first 325 pretty much stripped the shipyards of supplies, which it would take a while to replenish...
And with that sort of construction rate earlier on, compared to historical Royal Navy construction rates and bearing in mind what I've read about the two nations' relative capabilities in that respect, I strongly suspect that they only managed the first 325 so quickly because as those were intended for a specific mission rather than as long-term additions to the fleet the construction process focused on building speed rather than durability... possibly even using 'green' timber in some cases rather than the properly-seasoned timber that would have been in shorter supply. And if that
was the case then by the time they'd built that further 200 a number of the first batch would already be falling apart just due to contact with the weather & tides.
EDIT: And at that date copper sheathing, which was by far the most effective protection against both shipworm and fouling, hadn't yet come into use... so they'd have a half-year's worth of
those problems, too.
Also, could they have found enough additional trained seamen to crew those extra 200 transports properly? That was a field in which France definitely
was at a disadvantage compared to Britain...