As I've been learning about LGBTQ+, I've realized that the only pride flag emojis there are are the transgender and LGBTQ+ flag. If you think there should be more, remix and sign this and add your flags if you want (also, I did say I was asexual, demisexual, and a straight ally, but I've realized that those terms don't really fit me. I now identify as demiromantic, asexual, genderfluid, and polyromantic). If you don't want to add your pride flags, you could add the ones you want an emoji of. Of course, that's also optional. I've also noticed that there isn't a straight/ally flag OR a cisgender flag, and I think that's unfair for straight people, cisgender people, or straight allies.
Credit to Google for the pride flag images.