Debatable.
It's unprecedented but the military doesn't really have a legal mechanism for choosing whose the legitimate Commander in Chief.
It's more and more looking like Republicans will either try to overturn the results or refuse to accept the legitimacy.
Let's say Biden is swears in and Trump swears in. Independently of each other.
One has control of the civilian infrastructure of the military (Trump) the other doesn't (Biden).
Whatever happens here, I think the military will sit this one out and just fall in line with the eventual outcome.
I think people who place their faith in the military to step in and save them...are deluding themselves with wishful thinking.
Also anyone who thought that Republicans after an initial phase of denial will eventually gradually come to their senses and take a step back from the brink and drag Trump with them were also deluding themselves.
Tho opposite has happened and is happening.
I've said on election night, this is only over when Trump is no longer in the White House, even then this won't be really truly over, assuming Trump doesn't just stay on.