Deadpool just opened to 132 mil last year in his first solo outing, despite it not being in Summer and being R-rated. We saw Spider-Man make an adjusted 152 mil OW at a time of tremendous CMB skepticism. Heck even Iron-Man, who at the time was a B-lister at best, practically got a 100 million 9 years ago.
WW is an A-list superhero, a household name, and by all intents and purposes the most famous female superhero. This is more than doable for Wonder Woman, even if it fails to reach 150 mil, it should not be that far off.
Yes, I mentioned Spider-Man already. IM1 adjusted is $111 million, quite a ways off. I did forget DP, but he's a gigantic outlier in a movie that's not comparable to WW at all.
Wonder Woman, the name, is known in households. But the character isn't a household staple by any stretch. Outside odd the DC animated universe, she's really done nothing outside of BvS since her live action show. Most people couldn't tell you anything about her outside of generic power guessing and her lasso.
It's not hitting $150 million, severely better known and more popular characters haven't. $100 million is very doable, but that huge number is setting the movie up for failure.