It's tough to say for sure, but given how depressed the box office is for this type of films (The Bad Guys opened to $23.9M, Encanto to $27.2M, Sing 2 to $22.3M, Tom & Jerry to $14.1M, etc) it's really tough to suggest that Lightyear's $51M is somehow unreasonably low and a result of people protesting it due to that "issue".
Of note, most of the articles I am seeing calling this a disappointment seem to be basing it on (1) missing projections and (2) not winning the crown this weekend with Jurassic World having higher box office. Both are which are fair comments but don't really say all that much about Lightyear in absolute terms. I've even seen articles stating Lightyear is a bomb because it fails to meet the box office of pre-pandemic Pixar films which seems... odd, to say the least. Does anyone thing that comparing films today to box office from 2019 or earlier makes any logical sense?