I'd be rather surprised if Mauchly and Eckert knew
what
Turing-complete meant when they designed the ENIAC.
I don't have any knowledge of who wrote what and when, re: Wikipedia.
As for "did M&E know about Turing" .... good question! The answer is
"almost certainly yes" because von Neumann knew Turing.
As for * when * von Neumann taught M&E about Turing -- if they didn't
already know -- that's something I will try to find out.