The Nissan to Tesla connection wouldn't be J1772, that's AC and is pretty much a dumb connection.
It would have to be CHAdeMO to Tesla, which is DC and would require a software and hardware protocol translator. CHAdeMO is an open system as it's being publicly installed at government expense, so Tesla could build a CHAdeMO to Tesla adapter and expect it to work.
Superchargers are proprietary, there are no government installed ones, so it's not clear that a Nissan supplied Tesla to CHAdeMO would be allowed by Tesla software.
As I've said before, I expect that both CHAdeMO and Tesla DC charging will be superseded by the SAE standard, at least at public stations which will likely be the most common.