You reckon MS\Sony have any leverage to let themselves show the first next gen footage?
The consoles are pretty much known now with a solid release window, all most folks that dont care about the hardware side of things are eagerly waiting for that first true glimpse of next gen graphics, and why not show it at an event that had a total viewership of 26.2 million at their last showing and will probably increase more this year? Especially if MS wont show anything at X019.
I mean think about it, i highly doubt that either X019 or a one time event like a PS meeting 2020 will have more total viewers then TGA 2019, id be shocked if there even close, TGA is a behemoth at this point, and a damn good staging point to start next gen.
Imagine Sonys plan, show some next gen games at TGA = get people hyped for the PS meeting leave em wanting more at TGA.