I mean I know what is generally meant when the term gatekeeping is used but it seems like those that throw the term around consider something as simple as asking what comics they like to be gatekeeping. Is it as simple as that?
I remember when they announced the writers for the Star Wars High Republic series and besides the fact their twitter posts were full of "white man bad" nonsense she mentioned how empowering it was to see a female Jedi on screen. Of course she got mad when people pointed out there were female jedi in the prequels. Her defenders were calling everyone gatekeepers.
Also, there was the lady who is producing the new She-Hulk movie. She got mad because someone asked her if she is familiar with the character because the guy was concerned since so many of her tweets were about how evil white male nerds are and how horrible western canon is. She mentioned something about gatekeeping but I would think it is entirely reasonable to expect someone who is given a comic book related project to know the source material. I am currently on season 2 of Babylon 5 but if they ever did a reboot or sequel and asked me to write for it, you can believe I'll spend at least two months cramming on all the B5 lore I can find.
Sorry for the long post, but I would like your input. It seems to me that those that throw around the term "gatekeeper" are people who are mad because someone may have asked them something pertaining to the hobby.
But what do I know. Entering a hobby/fandom and then complaining about how it doesn't cater to you and insulting people makes perfect sense I guess.
Three point guide:
Did someone do something that made another person look like they don't know as much as they think they do?
Was one person "privileged" in some way, whether is be due to race, sex, sexual identity, immigration status, or religion?
Was the person who made the other look ignorant the "privileged" one?
If you answered yes to all three, it's gatekeeping. If you answered yes to the first two and no to the third, it was an empowered moment where truth was spoken to power.