I'm a cis dude, but only bc that's what is easiest. If everyone were to collectively decide I was no longer a cis dude I wouldn't care. I don't really have preferred pronouns but I usually just do he/him cause I don't really care and that's what I present as. I should probably just consider myself agender, but again that seems like too much effort, so eh.
I think, given the fact that cisgendered-ness is more or less compulsery and something that needs to be "opted out" of, anyone that finds themselves doubting being cis at all could benefit from doing some research and reflecting on their gender. If they are actually cis but maybe they are just chafing under rigid gender roles, that'll become apparent since finding out you're trans is more of a sudden reframing of a bunch of life experiences and struggles since childhood. I just think more people that are ostensibly cis but struggle with gender ought to check in on themselves and see if there is anything else going on.