Being new to MTH, I was hoping there would be one in the last catalog
It is true that the current state of the business seems to preclude any new molds for models that have previously not been produced, and MTH's plan does seem to be to reproduce in PS3 models that were previously released by them in PS2.
MTH is one of the makers who has previously made the I1s decapod and in light of their current process, are most likely to produce it relatively easily again with PS3 at some point. Whereas Lionel does not seem to have a mold for it. But this model in particular, like the MTH L1s Mikado, is very difficult to find on the secondary market, unlike other models such as consolidations, M1a/b, etc. Further, it has been quite a while since the PS2 decapod was released and I just wonder how much longer a wait it will be for a PS3 version. It seems to have been forgotten about by MTH or more likely determined not to be a good pick to produce. I don't know.
I would have thought that the PRR being popular among modelers, the PRR decapod being so prolific on the PRR, and it being in short supply on the secondary market would make it a good model to produce. On the other hand, I noticed that the PRR G5 is in the 2016 v2 catalog and is again in the 2018 v1 catalog, so there must be a decent size inventory remaining, which would seem to caution them against producing another PRR locomotive at this time. Also, if the G5 had sold through, maybe that slot in the 2018 catalog would have been the decapod, who knows. Side note: I have the PS3 PRR G5 and it is really a terrific small passenger locomotive for shorter commuter type trains.
I would prefer a decapod in PS3 since it does not have the tether like the PS2 version, but at this point I am not holding my breath and if I can find a PS2 version, I will go for it.