Again, I understand the argument. It's about giving openly gay actors more opportunity. But I think this argument is a double edged sword for THIS role. It's a gay character, but does his gayness have anything to do with the plot beyond comic relief? If it's played as a stereotype of an effete gay male, would a gay person want to be associated with it? We don't know yet. We also don't know the casting call for this. Did it specifically say "straight actors only"? If so, then yes, that's a problem. But if this was an open call, and the actor was the one who had the performance the producers were looking for, isn't that enough?
I can understand if they were making a movie about the gay experience, be it fictional or not, so hiring a gay actor or actress could enhance that performance (Although one could argue that Call Me By Your Name and Moonlight featured well received praise for straight actors in gay roles). But this is Jungle Cruise here. I don't think it's a movie that is necessarily going for a social commentary message.