Like you, mathematics is not my friend; but I think this story is fascinating. My sense of it is similar to your conclusion, especially from these portions of the article:
To complete the proof, Mochizuki had invented a new branch of his discipline, one that is astonishingly abstract even by the standards of pure maths. “Looking at it, you feel a bit like you might be reading a paper from the future, or from outer space,” number theorist Jordan Ellenberg, of the University of Wisconsin–Madison, wrote on his blog a few days after the paper appeared.
In December 2014, he wrote that to understand his work, there was a “need for researchers to deactivate the thought patterns that they have installed in their brains and taken for granted for so many years”.
Yup....and this guy is totally capable creating a entirely new branch of math that could in time expand and all the high flyers will be trying to break it, and create even more mathematics that can now be used to solve or pose even more potential questions in mathematics.
I cannot imagine what that might mean to....physics and other sciences.