I wouldn't say Metroid and Castlevania merging into the name of a new genre label is quite the same as expecting every game with the word "Soul" in the title to be a souls-like.
Rogue has a similar problem sure, but I don't think it's at the point of expecting every game using the word to be a Rogue-like. Recent example 40k: Rogue Trader.
Someone's got to crunch those numbers.