It will be trash all its own! Besides, if they weren't called Caitians on screen... well you all know the drill.
Well, since the Caitians were never called Caitians on screen we don't have to assume that a possible reimagined alien that's referred to as a Caitian belongs to the species that we commonly refer to as Caitian.
There's no way in Hell that they were ever going to make those two gorgeous women look like actual pussy's for Kirk to hump in a major motion picture...
Neither were the Saurians ever called Saurians on screen (that I'm aware of). So, unless these new "Saurians" are identified as such on screen, then they can technically be anything.
It is actually a very wide open point-of-view. It doesn't unnecessarily chain future creators to anything that isn't considered important.
There is a lot of info we take for granted that didn't come from 'on screen' canon. Ship class names, ship lengths, species names.. Alright that actually isn't a lot.
Except the examples I used have come from people who worked on the show. No one who worked on the show said Spock was the first.
Bill has been here since 2001, were there many discussions back in the day about how T'Pol couldn't possibly exist since Spock is the first Vulcan in Starfleet? Also, Kirk being the youngest captain is another such fanon thingy.
You obviously weren't here when Enterprise was on the air. Many thought that was canon. Many people were gnashing their teeth over it, wanting to go to war with Berman and Braga.
Except people who actually worked on the show are a lot more reliable then fans. Anyways the whole 'on screen' is canon thing is an invention by the fans, I don't think there was ever 'official' rules by CBS/Paramount.
Well, until the next set of writers come in the door. Pretty sure it was somewhere along the line. But there are people around who have more knowledge of such things.