/locate command doesn't take target/coordinate arguments

When [Mojang] Jeb (Jens Bergensten) announced the locate command at MineCon 2016, he mentioned that it takes arguments to determine where to start the search from (e.g. @p, <x> <y> <z> etc.). However this doesn't appear to be working.

I've tried the following commands, all of which fail.

/locate Mansion @p

/locate Mansion 1000 100 1000

/locate Mansion ~ ~ ~

/locate @p Mansion

/locate 1000 100 1000 Mansion

/locate ~ ~ ~ Mansion