That would make sense. It would also explain how Samus absorbs the Core-X's power. Maybe a Metroid just needs the means to use an absorbed ability (a mouth, a gun, etc.) in order to use it.
Well, Metroids can absorb energy, so it'd make sense that they can replicate said energy, like the X. IIRC, the Metroids are basically like the X, but without the ability to take control of hosts.