Solo had around 60 something per cent on RT before its release. And i remember outlets like Collider and IGN being extremely luke warm about it (their reviews are still up on their sites). Some hardcore Star Wars fans liked it (like Campea and Schmoes) but by and large, it wasn't praised. That being said, we can't make a direct comparison to CM because we don't know what CM's critical reception will be like (we've only gotten screening reactions).
Solo was a mess because of a change in directors very,very late in its production schedule. That's what even drove up the cost to the around $300 million, it was an abnormal production.
According to boxofficepro.com, Captain Marvel is still tracking to open at $160 million,
https://pro.boxoffice.com/long-range...ecord-opening/ it hasn't dropped (the link includes the tracking for other movies). Different outlets are just giving different figures based on their data, we will get Disney's official tracking closer to release. I don't think Captain Marvel will open to $160 million (that'll be monstrously high for an origin story for a hero not introduced in a previous Marvel movie) but it should get to over $100 million, anything less than that and it will have to have very good legs.
That being said, box office tracking isn't an exact science, it's based on a combination of social media activity and pre-sales. Forbes magazine pointed this out a couple of years ago when Civil War (?) came out far below tracking but people are treating it like an exact science, it really isn't, that's why a substantial number of movies rarely open to around tracking numbers (lots of times its higher or lower).