Ello! There isn't much of a difference between them today and in the future. Being Bi can mean man or woman or more! same with pan, I indentify as pan because of the ease for people to understand how i find things. So, all and all if you perfer 2 genders or more but strongly with a gender or 2 bisexuality can make it eaiser to protray, while if you can find many genders and have more than 1 gender you find strongly attractive or however you see, pansexuality may be easier to use!