I wonder if the Greenskinz Orrucks as big waaagh battleline on the azyr app is correct. Certainly interesting if it's true, but I guess an faq is required.
I hope not, but expect a "without the Greenskinz keyword" clause in a faq. The Orruck synergies are a mainstay of GA Destruction, it'd be such a bummer to lose them just so GW could spite people who bought the AoS products they sold.
The Mighty Waaagh requires the Orruck keyword only, which Greenskinz have. It's at the start of the book. Greenskinz are legal until faq'd or legends replaces their keywords. Legends afaik is going to be matched play legal too; GHB 2018 deliberately stated as much.