There are rumors confirmed by several sources that the announcement of a new Montage is imminent, 7 years after its marketing: a suffix will be used for the name similar to what was done with MOTIF (the possibilities are the Classic +, Plus , ES, XS, XF,..).
For obvious reasons it is not known what the new features will be and therefore it is possible to make only hypotheses.
The first thing that will interest you is whether there will be a parallel firmware update to the current Montage (compatibly with the differences) or if, on the contrary, the latest version will remain 3.51, perhaps updated for some bugfixes or small changes.
Regarding the news, it is possible to make only hypotheses.
The first possibility is the inclusion of the AN-X synthesis engine whose trademark was recently registered (June 2022). As repeatedly said, to date it is not known whether the current SWF70 chips present in Montage are able to generate sounds with different synthesis from AWM2 and FM-X, and the eventuality of the AN-X synthesis generated by a new chip , would cut out the current Montage.
The second possibility is that a path similar to that followed with MOTIF is followed: a maintenance of the synthesis, perhaps with small changes, and an increase in polyphony (AWM2 128->256 and/or Flash memory dedicated to user/presets multisamples). In this case, without upsetting anything, Yamaha could follow the path followed with the Genos arrangers, where the second SWP70 chip (slave) which in the Montage does not have Flash, could have 4 GigaBytes of flash dedicated to User samples and/or new multisamples presets (see for example the excellent Bosendorfer already available as an additional library). We will see.