From what I read here if you send in a 4X and they can't fix it how can they replace it if they don't make 4X scopes anymore?
They will either send it back to you or offer you a similar or similarly priced replacement. Your choice.
That’s pretty much standard practice for any company. Once parts are exhausted for a product line, that’s the end of repairs, unless you go to some aftermarket repair outfit using salvaged parts.