No, I think it was a cloned version of Ridley that eventually melted, allowing the X to assume its globular form and float away. The ice just broke away at that point. I think it was always an X clone.
My interpretation only.
Still doesn't explain why Ridley was on SR-388, though.
Adrock, Zero Mission is the new canonical basis for the Metroid games. Since Ridley was the general of the Pirates at that point (or whatever), he or his CO must have been ordering replicants of him to be built before he attacked Zebes in the game. I think that Mecha-Ridley was an early, failed experiment, or prototype. By the time the Prime games come around (like two or three years later), the Pirates successfully created a robotic version of Ridley, and they sicked him on Samus.
Samus blew his **** up, and he went flying down a canyon. The Pirates must have recovered his body and either fixed him up (stronger, faster, better than he was before) or built a whole new improved model that appears in Corruption.
Since Zero Mission references Prime, it's canonical. Since the Prime games are canonical, and Corruption references Hunters, it's also canonical (sigh).
I'll be interested to see if there are any allusions to the Prime games in Other M.