A lot of basses come with mixed hardware. I have a factory 2003 MM Stingray which has nickel tuners, but chrome bridge and chrome control plate.
Most older Fender Jazz basses are that way too. Nickel tuners, chrome control plate and bridge.
From what I can tell, chrome pits with age if not taken care of, whereas nickel just gets oxidized... much easier to polish oxidized nickel, than try and get pitting out of chrome plating.
I prefer nickel hardware, but it's hard to find all parts in nickel. Things like neck plates and control plates are impossible to find (maybe I can't find them).
On the other hand, seems as if everthing is available in chrome.
Hope that helps.