After discussing with product, { splitVector ... }  will be just an alias for autoSplitVector. 

splitVector and autoSplitVector have 2 different signatures while still behaving very similarly. 

The following parameters are not present/or called differently in autoSplitVector and will no longer be supported:

maxChunkSize, maxSplitPoints, maxChunkObjects

the parameter force, will be supported by the splitVector/autoSplitVector until 8.0 as still needed for the router spit to calculate the median key.