As Ross already stated in his comment, the inability to move apps to SDCard has nothing to do with Android ICS (though several manufacturers claim exactly that, it's simply not true: AOSP1 supports this since 2.2-froyo and at least up to 4.3-jelly-bean. Only with the "security change" of completely disabling free write access to SDCards with 4.4-kitkat, this feature became unavailable.
So whether an update to a higher version of Android brings back this feature to your device, depends on several factors:
- if the update is provided by the manufacturer (stock-android), question is whether the manufacturer re-decided and left the option in – with the exception of Kitkat ROMs, where they are unlikely to do so.
- if you're planning for a custom-rom, it's unlikely that will ship without this option. It might even have brought it back to Kitkat (the fix required to do so is not that hard to achieve) – but you might void the warranty of your device that way.
1 Android Open Source Project, i.e. the Android code basis ROMs are based on