I have a feeling Wilder is just clowning us all with this remark. He is calling out Wilder and Joshua now, only to end up fighting a Pulev, a Whyte, or a Stiverne (again) in his next fight.
Cherry Wilder fears even this old and gun-shy version of Wlad. If Szpilka and Molina rocked and hurt Wilder, it isn't hard to imagine what would happen when Wlad and Joshua connect upon Wilder's shaky whiskers.
He will probably bottle out of fighting Povetkin -- again -- should Povetkin beat Stiverne. Hence why he is using Wlad's and Joshua's names as leverage.
That's one I'm struggling to work out, too. I hope Wilder is mandated by the WBC to fight the winner of Povetkin vs Stiverne, and isn't allowed to just fob off the mando commitment by cherry picking Dillian "The Dipstick" Whyte for a voluntary defence. This way, Povetkin will get by Stiverne, Wilder vs Povetkin will be unconditionally made, and Povetkin will proceed to ruthlessly annex the WBC title from Cherry Wilder.
He didn't even beat the Z man the first time around. Wilder hit Charlie Z while Zelenoff was on the floor -- meaning, Charlie Z holds a DQ win over Wilder. And Lesnar would scream at Wilder, then take that Cherry-picking jabroni to Suplex City.
Pretty sure Povetkin has been cleared, he used a substance which WAS legal when he used it and there were still traces after it became illegal - understandable that the organisation put a hold on things and investigated, and considered things after the fact to make sure everything is handled correctly. Tricky situation at the best of times.