Well, the quick answer is no, none of them are a direct fit.
TCX top, Pro 4 bottom. I didn't realize they were identical, but they are.
Pin diameter on the TCX/Pro 4 shafts are 2.37mm.
Pin diameter on the stock Sport 3 dogbones are 1.97mm.
These Tamiya shafts have have the correct pin diameter, but they are only 44mm long. I'm pretty sure tamiya has a 46mm version, using the 46mm shaft is a possible solution, but I can't confirm it will work for certain as I don't have Tamiya 46mm's on hand.
And last we have the CVD's out of a Sprint 2, everything fits and the pin diameter is correct, unfortunately the shafts are way to short though.
If you have have TCX/Pro 4/Sprint 2 CVD's and tamiya 46mm shafts laying around, then you could probably make it work, otherwise I'd just wait for HPI to release the proper CVD's.
I'll keep digging through all my parts bins to see if I can find anything else to try.