Do i need to do witch queeen campaign or just own it to get hoarfrost z from legend lost sectors

[OurNathanStar]

Ive done many and getting non legend sector exotics

[N33MA]

Just need to own the expansion

[Comrade Pickles]

Not sure if this is helpful but this exotic dropped for me from the Vex Incursion Zone in Neomuna.

[Kylito]

Don't know for sure, might aswell do the campaign. My hunter hasn't completed the WQ campaign and still has all exotics.