Whatever the details are, I am interested if it set a precedent or not.
No precedents were set here, what the general did is just leadership. he explained what the rules were explicitly to his followers, to ensure that trump didn't collar one of his followers and somehow ram a nuclear strike through without proper approval.
See "Operation of the Nuclear Football": https://en.wikipedia.org/wiki/Nuclear_football#Operation involves informing the SoD and JCS.
naturally, it's far more complicated than that, https://www.armscontrol.org/act/2021-06/features/nuclear-lau... and no precedents were set in this situation.
[1] https://www.cnbc.com/2021/09/15/milley-held-secret-calls-wit...
Time will tell.