I think its more a push toward making space for people who have marginalized identites to act. For a long time being openly queer was career suicide. So now that those stories are finally being told, people also want actors writers and producers of those identities involved in the process.

I think its less that straight actors cant play queer characters and more so that there are already plenty of roles for them. Maybe in a more equal future that pressure wont be there but right now it is.

I also think it depends on the role. A side character that happens to be gay? Yeah a straight actor can definetly play that. A lead role in a comming of age tale about discovering your gender identity? Probably best played by someone who has lived experience.