By that logic, ethnic Europeans are the 'original inhabitants' of North America.
I'm also unclear on why you quoted what the British did in your post - how does it relate to whether or not calling those people 'original inhabitants' is misleading? Do you believe that, if the British did something sufficiently wrong to them, that calling them 'original inhabitants' will be less misleading?
Not everything is a contest. It doesn't matter how "original" natives are if they're natives.
The reason "ethnic Europeans" aren't "the original inhabitants of North America" is that European settlers violently displaced (or killed) the previous inhabitants.
Heck, the "original" inhabitants of North America (as far as we know) actually originated in what is now mostly Russia if you go back a few dozen millenia. And if you go back further than that (according to mainstream scientific consensus) we all likely originated in Africa. Defining the term "original inhabitants" as an absolute is blatantly begging the question (specifically it only works if you're a creationist).
People were subjected to physical and psychological violence to be forcibly removed from their home and birthplace. That's bad enough, no matter how many generations lived in the same place before. This isn't about who's had it worse.
They were expelled in 1965. The current year is 2017. If we wait a few more decades this discussion will be pointless either way.
I'm not opposing clarifications. I'm opposing quibbling over the semantics of "original" as if the distinction adds anything to the conversation.
Their parents lived there, they were born there, they were violently expelled and suffered emotional abuse. The number of dead ancestors (or lack thereof) in the ground does not invalidate the suffering these people were forced to endure.
I'm also unclear on why you quoted what the British did in your post - how does it relate to whether or not calling those people 'original inhabitants' is misleading? Do you believe that, if the British did something sufficiently wrong to them, that calling them 'original inhabitants' will be less misleading?