It's definitely looking like less than $1B worldwide for this movie. RO was mostly adored by the fanbase (the intended audience for these standalones) and even it only made just over $1B.
Solo will also be the first to suffer from "franchise fatigue" - just too many SW films coming too close together. It will be the THIRD SW film in just 18 months, which is crazy.
And considering Solo was pretty much shot twice, nearly doubling the original budget (unpublished, but likely in the $150m range) , it may actually be the most expensive SW film ever made, and therefore the least profitable.
If the final Solo production budget is indeed in the $300m range (possible) and Disney spends about $100m worldwide on its marketing (likely - non-mainline standalone films are a harder sell) it would mean the movie wouldn't move into profit until the $750m range (depending on whether Disney secured the same unprecedented 65% take they did for TLJ.)