Thing is, can that gag order be imposed without a judge in the mix?
It seems reasonable to require lawful gag orders to be confirmed by the judicuary, not just issued at will by the executive.
In this case, they just sent that "preservation letter" and in the letter said not to alert the user: Techdirt (somewhat reasonably) is portraying that as "effectively" a gag order. They didn't go on even to issue a subpoena here, and so they also didn't go get an actual gag order, but it's something they've been known to do.