I think it's on at 5 PM for me.
First Aid class finishes at 3:30 PM and then I need to do a little grocery shopping, so I think I will be home in time and won't have to wait long after I get home.
I don't have any major expectations or hopes that I think will actually be fulfilled, but I just want to see only Switch games in the Spotlight (I won't mind if they have one or two 3DS games as long as they are brand new and meaningful), and I want to see mostly new games we haven't seen before, preferably legit looking games and not more filler like most of the past two years for Nintendo. I won't even mind if most of them are 2018 games, I just want to be sure there is a lot coming.
I also don't want to see Rabbids in the Spotlight because we got a solid first look already. I look forward to seeing it in the Treehouse though.
Super Mario Odyssey, Fire Emblem Warriors, and Xenoblade Chronicles 2 will probably be there. Mario will likely get a 5 minute "spotlight" at least since it's their headline game. Everything else should just be 2 or 3 minute trailers back to back. With that estimate, we might see roughly 10 games (probably 8 to 9) besides the ones mentioned above (both first party and third party), accounting for the intro and outro, and the possibility of a skit as well as amiibo announcements.
I feel like this is a fairly reasonable expectation, given Nintendo's current situation and strategies.
As for the Treehouse, they can do what they want.