Why?
There is nothing really strong being released throughout March to compete with it at any level.
The next movie that will is "Dumbo" on the 29th, but in the comic book /superhero sector theres only "Shazam", and thats due out 5th April, followed by" Hellboy" 11th April and then a small, relatively obscurely titled genre movie that nobody has any interest in at all called "Endgame" on the 25/26th .
So its going to stay top of the BO for weeks.
And, if anything, the arguement for a big drop is very likely to be wrong because of that.
An "A" average usually translates to a very good word of mouth trend from the general audiences, so more people are likely to go see it based on the recommendations of others . I certainly will go see this this week because I usually always steer clear of the first Friday/Sat/Sunday opening weekends because of the crowds.
And it was a "late" opening for a MCU movie, usually we'd get an extra day in the UK, like a Thursday, which didn't happen for a number of the international markets . And that was true of the US as well.
Also, if there really is that strong support from the SJW contingent in opposition to all the negative social media attacks, thats likely to continue for some weeks.
Personally I don't think this will matter that much, to the same degree the boycott didn't. The percentage of people who would be affected or would want to deliberately effect the movie based on this debate is a very small number of the overall cinema going population. People just want to have a good time at the movies and CM delivered this for most based on that "A" rating.
So if "Aquaman" can deliver a billion I see no reason why CM cannot get close to that.
I'd also add this youtuber (Beyond the Film) comments , who delivered one of the most balanced reviews of the movie and the BO performance I've seen so far: