Ant-Man came out in 2015 but you are correct in that the only other MCU movies it beat in Thursday previews are phase 1 movies (Iron Man 3.5M, Thor 3.2M, Captain America 4M and probably The Incredible Hulk but I couldn't find the Thursday numbers for it)
You forgot
Iron Man - Ironheart
Steve Rogers - FalconCap
But with the exception of the original characters that have died (Steve, Tony, Natasha, T'Challa) none of them have been replaced by the younger heroes.
So, I did some digging to see how The Marvels will fair against other low-grossing MCU movies internationally.
The Incredible Hulk made 33M during its overseas opening weekend.
Captain America The First Avenger was at 53.5M by the end of its international opening weekend (rolled out a week after domestic opening).
Ant-Man made 57M during its international opening weekend.
Didn't include Thor here because it actually opened internationally a week before domestic and made 93M.
Iron Man - 3.5M
Can somebody find out what the Thursday previews for The Incredible Hulk were because I can't. But it's kind of pointless comparing phase 1 previews to The Marvels considering that Thursday showings started way later back then.
If that's the reality we live in then I hate it. It's the same as saying that Ryan Coogler really should have shoved a white co-lead into the Black Panther movies. The fact that he didn't need to do that for white men to show up for those movies is even more depressing somehow. It means that men can look past race but they can't look past gender.
As a man, this is so alien to me. "If a man isn't the lead then I'm not watching it." I grew up on stuff like Alias, Buffy, Charmed, La Femme Nikita (the 90s series) and Xena so I've never had an aversion towards female-led series or movies.