Well in accordance to
THIS panel from the english scanlations, universe which we follow (the ones bearing the teen Ryoma, Hayato, and Benkei) has their respective Saotome Institute conducting, and in the words of nondigital Saotome in response to Ryoma from the second-to-top-panel "that much like us, they're also carrying out simulations with virtual worlds?!". You see, this line insinuates that so too the nondigital counterparts are conducting virtual simulations, digital Saotome proceeds to say that "Given the information one can obtain from it, it's quite natural that I should be able to realize the world I was in was virtual. Midway through as the simulations repeat the Fragment of The Emperor, alongside what one should call the memory of the Getter Rays is born..."
Now, as detailed on both this wiki's page for the Getter Emperor, and the Getter Ray page on the Getter Robo Wiki,
Getter Rays govern,
"matter, spacetime, and energy itself", even capable of containing the souls of the dead, such as how Saotome from New Getter Robo was capable of communicating with Tatsuhito after the New Getter murdered him upon his transformation into an Oni.
Now, since we have evidence that these worlds are indeed virtual, how the Getter Rays govern certain key aspects of reality itself, and their ability to contain information, it seems that the nondigital Saotome Institute is running these simulations, having their results encoded onto the Getter Rays, and then utilizing these encoded Getter Rays to generate the next batch of universes (much like a genetic algorithm), this means that, whilst the universes themselves are not real, the Getter Rays had encoded upon them their information and the unique merits of the Getter Robos generated by each universe, ultimately culminating in the "pinnacle of evolution", the Getter Emperor.
So whilst I wouldn't say that the Getter Emperor *generated* these universes into reality, it had encoded upon the Getter Rays the information regarding each digital universe, regarded them as no different from a nondigital universe, and ultimately complied all the information into a clone of the Getter Emperor generated from the semantics of these universes, bringing along Ryoma once the Original Getter is deployed at the end of the manga within the nondigital universe, inducing a metamorphosis into the Getter Emperor via Getter Rays, a metamorphosis of which conjures digital Ryoma into nondigiality,
per these screenshots of the panels.
Note, per the finnikyness of my laptop and imgur in tandem, I could post the panels in the correct order, so if you attempt to read through, I suggest you scroll to the bottom, and read upwards from there, not to mention the partially cropped additional images generated by imgur, I believe only five exist throughout the whole 35 page collection, and they dont disrupt the flow that much. So yeah.
