"Some of those games are even using top-down view instead of platformer in fact. But that's my opinion and I have no right to deny those developers."
That is not just your opinion, this is what a metroidvania should play like, but as the person below you mentioned, some developers will incorrectly label their game on purpose because it attracts attention to their game, but not always it could also be an accident or a misunderstanding of the genre.
You should not necessarily dismiss the game or the developer because of a mistake, but if the mistake is flagrant then I think many will agree with you and ask the developer to rectify this issue. At least the metroidvania genre is pretty well defined among players, so that should not be too big of an issue to address.