Someday it will, but not until the new version includes this feature and a few others. It is the reason the v1 is still available. And you will get ample warning before it is sunset.
Has the latest API version have something like createOrUpdate contact endpoint?
SOLVE
It's been 2 years guys. In the meantime you build new features you can charge for. Spend some time on what existing users need please. Feel free to escalate this... also it would be amazing if a new version of this API allowed us to state some fields if already filled out should not be overwritten (like don't overwrite firstName or lastName if already existing for example)
Someday it will, but not until the new version includes this feature and a few others. It is the reason the v1 is still available. And you will get ample warning before it is sunset.