Well, from a plot stand-point, it might have been a bit of a risk to come out after Infinity War. In fact, I remember DC fans accused Marvel of ripping off their story at the time. (They didn't, it's a common trope and both groups had come up with it in the comics ages ago, and played it out differently. There are no original plots, just original ways of conveying them.) But I remember that being a factor in regards to release dates at the time.

That said, you raise a good point about the AT&T/Time Warner merger. Having been in multiple companies and industries undergoing transformative change and mergers - I can say from experience - that's toxic in of itself. People do not tend to behave well when they are scared of losing their job, or feel that their job will change completely without their input. A chaotic work place tends to lead to hostility and bad behavior all around.

It also would lead to various people in charge pushing films to be released early. They want to add them to their resumes - before they are kicked out.