For gens you could make an argument about the price but not so much with reps (which is why they're here in the first place). You could argue that for the asking price, very similar models would probably dilute the demand but then that production model has been existing for a long time already.
Rep-wise, the newer models in the market are using in-house movements and new form factors such as the Due and 38mm sizes. The factories cannot seem to catch up with the trend, the latest push seems to be the replication of the P.9000/P.9001 movement but no more new developments beyond that. Since PAM rep collectors are becoming more and more discerning, making something that's 3mm thicker than the gen simply won't cut it nowadays. Look at the PAM777, still just on the first page of the new releases from Puretime and it was already discounted, maybe because of the feedback regarding the dial and the movement.
Then you add to that the departure of Noob from most of the PAM replica seen a few years ago and the closure this year of H-factory. They were at the time, the biggest producers of PAM reps and a very good rivalry between them resulted to a lot of models being produced, even releasing the same models on a head to head like the PAM243. Now the only factory making PAM reps is VSF and its little sibling XF, from its KW/V6F legacy. ZF is still producing a few but not so many.
In comparison to Rolex, things have largely remained stable in terms of the watch movements and cases, so the rep factories can focus on continual improvement, no need to make the next movement or the next case design iteration. Officine Panerai is continually evolving with new materials, new movements and new case designs (not radical but still different from what is existing). We've hit a plateau of sorts, we're waiting for the next one to appear. Time will tell.