That's the thing, How is the term of Exception even defined. because depending on how you define it, there is a bit of argument to try to see Exceptions as a standard
If there's reasoning based of why something is an exception, and why it couldn't apply to most things, and these reasonings have no room to change or be defiled to a falsehood, than it makes seens to see Exceptions as exceptions
But I would say in this case, the examples shown are exceptions because we haven't seen it happen before. By that logic, all the Inventions that we have gotten, at the time they were invented, were seen as exceptions to the state of things. Not just technological advancements like Lightblub and TV, but also things like birth of Democracy, or Different types of art defined by periods like the enlightment, or Guerrla Warfare
An example I would say is Super Sayian. It was said in legend that there was only one Super Sayian, and Goku seemed like he was the Super Sayian legend spoke of. At that time Goku was an exception to the rule, and we couldn't treat Super sayian as the standard. Now Super Sayian is like a Bargain sale, as It's probably easier to name Sayian that weren't shown to have Super Sayian
Ultimately, when it comes to those Exceptions, it's up to those affected to see if they want to go in that direction. They could either go with what the exceptions show, or they could continue to evolve the standard they are accustomed too
Regarding Smash, because 3rd parties are a variable that's changing, I would say alot of time we won't get as many music as Terry did, but there are cases like with Touhou or perhaps any of Falcom where the exception is Plausible and would be new standard