1) Due to natural inertia there exists to leave things alone that aren’t overtly broken, I doubt there would be a lot of cases in which people would feel so inclined to convert to a different format
2) If people do need to convert it, at least it’s a simple enough spec that conversion shouldn’t require a Herculean amount of effort (I bet there already exist converters that others have written)
If you have such a person anyway, you can just let other contributors write simple text without any styling to begin with.