Yeah, I think because there's three A-level titles opening in less than a week's time no one wants to predict a blowout for any single one of them and be proven wrong. Not to mention how very, very wrong the Thanksgiving predictions were last year; Wish was expected to be an easy first place for the holiday weekend, and boy that didn't happen, nor did the frantic hopes that it would be an Elemental-esque slow burn.
That article linked to actually gives a good breakdown of why the projected numbers are what they are: Wicked has stronger presales than Gladiator II in part because women are planning outings for it (as happened with Barbie), but Gladiator II is the sort of movie that could have more walk-up business from both men and women who aren't interested in Wicked (and some might make time for both). I'd also note that both movies are lengthy, which limits how many showings each can have in a day, and being Big Big Movies some viewers might wait until they can see them in a premium format like IMAX (this happened with the recent Dune duology, which helped them leg out in their theatrical runs), though this will be trickier with Wicked because Moana 2 arrives just 5 days later. In fact that also might be driving presales. Moana 2 will primarily be driven by walk-up business -- families with kids being what they are trying to book ahead could be derailed by all sorts of things! -- but that it is performing well in presales is encouraging.
The great news is that all three movies look to at least have strong starts. If any or all turn out to be good, so much the better, but the review embargoes haven't been lifted yet. Gladiator II did have a world premiere screening a few days back that apparently went well. Wicked's world premiere is this weekend. Social media reactions tend to be glowing most of the time so they needs be taken with a grain of salt (though if they're not wholly enthusiastic that could be a sign of trouble; that happened with, again, Wish), but given how confident Paramount and Universal already are about these films -- they've done a great job raising awareness, all things considered -- we might get the review embargoes lifted sooner rather than later.
An interesting thing with Moana 2 is that apparently, if you're not really tuned into Disney media and/or don't have kids, you might not know about it yet. In the social media circles I travel it's almost only talked up in terms of "Wait, there's a Moana 2 already?" So I guess the presales speak to Disney at least making the Disney families aware of it!