If the universe is correctly described by Tegmark’s mathematical universe hypothesis, it’s still the universe.
Edit to add: Considering a philosophy should worry you only if you suspect that your motivation for caring about your visible universe is based on some principle or idea that is likely to be invalidated by that philosophy, if it proves correct. I don’t think such motivations have a large amount of crossover with multiverse-type theories.
I think you are forgetting Egan’s Law.
If the universe is correctly described by Tegmark’s mathematical universe hypothesis, it’s still the universe.
Edit to add: Considering a philosophy should worry you only if you suspect that your motivation for caring about your visible universe is based on some principle or idea that is likely to be invalidated by that philosophy, if it proves correct. I don’t think such motivations have a large amount of crossover with multiverse-type theories.