Doesn't matter what is correct or what correct is?

When we're asking a question we use a reversed order of words:

Where is he?

When we're stating something we're using the normal order:

I don't know where he is.

But what about one?

It doesn't matter what is correct - if enough people make that mistake it stops being a mistake anymore.

Above I see the reversed order. Or maybe it just appears that way? At the moment of writing this I'm realizing that maybe it's not the case here since it's a verb-adjective pair instead of a verb-noun pair?

But anyway, maybe the alternative is correct then?

It doesn't matter what correct is - if enough people make that mistake it stops being a mistake anymore.

The alternative most certainly isn't correct, and your realization about comparing a verb-adjective to a verb-noun pair is correct.

In the second example, the pair ought to be highlighted as "It doesn't matter what is correct", and the word order is preserved.