Not, this would be like requiring cats to be added to older legal vehicles.
Nope - the EPA regs ban 86-on two strokes from on-highway use for pollution violation. This is exactly like cats - if you have a pre-cat car, you can operate it all you want without cats. If you have a post-cat-mandate car, you can’t, and if you have a post-mandate off-highway vehicle that didn’t have cats to start with, you can’t use it on-highway. That’s (sadly) the law.