I recently cleared my job assignments and put four kittens into each job, whether I needed them or not, so it would put the ones who were already best at those jobs into them. So I have four scholars sitting there being all scholarly, and my science has been capped for 47.75 out of the last 48 hours (I'm bottlenecked by steel, gears, and manuscripts at the moment, so I have nowhere to spend science). Even though they're not producing any science, they're still gaining experience, right? So when I break through this bottleneck (printing press, steamwork automation, and my first steamwork should all come tomorrow), they'll be able to put out the science as if they'd been doing it the whole time?
Yes. Any kitten assigned to a job will gain experience in that skill. They will also slowly lose experience in skills they are not assigned to, so you really shouldn't reassign them right now if you want them to remain top-quality scholars.