my first guess is a flock of canada geese flying south for the winter - with the light reflecting off of them. more or less a sloppy v-shape, which is pretty common for them.
Watch a flock of pelicans fly. When they flare off to turn, they seem to go completely invisible until they come out of their turn.
That’s my guess too.
Lit up from the lights as it passed the buildings below then winked out as it got out of range.
People act as if never happened before!
I’ll second that theory.