I'm bi-/pansexual and I’ve seen a whole range of reactions from potential partners as they learned that I’m Bi. The most shocking to me was having a woman respond with disgust who was also bisexual and very loud about being so.
I’ve had partners who were intrigued by the idea. Gay men are usually unfazed by the news.
If I look for another long term relationship someday, looking for another bi-/pan- and poly partner will be a priority for me regardless of my new partner’s gender identity or biological sex.