Platforming is also very much a regular requirement to achieve any sort of progress in those titles. Failure to platform efficiently will lead to far quicker death. Therefore they are within platform genredscross said:It's not a small number of castlevania titles - there are loads of them, it's just that Symphony of the Night helped popularise the style that became metroidvania, but it's not necessarily what they are most famous for if you are in any way familiar with the series, so castlevania is not in this argument.
But back to your original point about about whether metroidvania should be considered platformers - as far as I'm concerned, you jump around on platforms all the time. Ergo, it's a type of platformer. I've heard them described as 'explorable platformers' before. OK they aren't your classic style of platformers, but they still fall under the same rough bracket for me. It sounds like in your mind you need it to be a 'if you fall off the screen and you die' type of game for it to be considered a platformer to you. It's just two different types of platform games in my opinion.
These terms are nebulous tbh.
OT: Rayman Legends is the good shit. It contains content from Rayman Origins too, so I'd say it is the definitive option out of the two. Can't say if it's the best platformer evar, but it is indeed peak quality regardless of moderninity