I'm all for speculation when the writer doesnt tell us what is happening. But Coates, since Ororo was revealed to be a goddess, has been using that term - goddess- whenever hes describing her abilities. He even mentioned early on that her godhead goes much deeper than her mutation. So to collectively group this to some form of secondary mutation - ×while arguably makes sense - doesn't gel in the slightest to the stories he been telling since Ororo was revealed to be a goddess. As another close friend pointed out, storm's godhead was triggered again in shuri and all she did was shoot lightning and create a vortex of wind. Simply, Goddess Ororo can and should be able to do anything she normally would do as a mutant but the reverse isnt true.
That said, I wasn't convinced there was much difference between what she could do with the eceptiom of utilizing divine energy when in god mode but today has revealed that she has a deeper ability via her godhead to manipulate plants or at least create an environment where they can grow to their most optimal form. I would love more direct details to exactly what she can do as a god but he has provided us some detail of this. We know it's her blood right and she is powered by faith. Shes described as a bigger god than Adversary/Sefako and if we are to take coates for how she was literally described prior to executing the feat, she can manipulate plantlife.
I loved that version of Storm. Coates seems to be bringing the two closer together