The point is that with replicator technology, the whole concept of material scarcity goes out the window. The assumption that it's possible to run out of stuff without some separate factory to replenish it is 20th-century thinking. They should
be able to replace torpedoes -- it's a logical consequence of the existence of replicators. All you have to do is use your imagination to consider the ramifications of the technology and the conclusion is self-evident. They shouldn't have to spell it out.
The only thing in torpedoes that couldn't be replicated is the antimatter. Maybe that's what Janeway was talking about in "The Cloud." Now, according to the tech manuals, Starfleet vessels are equipped with "spin reversal systems" that can, with very low efficiency, convert matter to antimatter, allowing partial replenishment of the ship's supply. Maybe this component had been damaged, leaving them no way to replenish the antimatter payload of the torpedoes. But replicating the rest should be simply a matter of having enough energy.