Modeling amps, drives, compressors, and the analog sections of mods and time-based effects utilize DSP tools that describe the behavior of those circuits. If you've created, say 100 tools, you can describe the behavior of X number of amps and effects. Some amps and effects might not sound right because your 100 tools are insufficient, so you improve your tools or create new ones, all designed to work within the limitations of your DSP architecture and chipset horsepower.
The next generation might have more DSP so it might afford notably more complex variations of some (or most) existing tools and some all new more DSP-intensive tools, but some tools that work very well might be kept the same. Decades later, your original 100 tools may have ballooned into 1000 or 5000 tools and maybe all but a few of the original tools have been deprecated.
With Agoura, we pivoted to a different approach to the amp modeling process itself, which means (at least for amps) moving most of our existing DSP tools to a storage facility and then buying a whole new set of 5000+ brand new tools in an all new much bigger workshop, with room for continually growing our toolset for the foreseeable future.
There are 22 items in the Amp model list (16 guitar, 6 bass), but 40 total channels. So if you count models like we did in Helix, Stadium 1.0 will introduce 40 Agoura amps.