Fortunately the thread title now reflects the actual subject and saves us from mental gymnastics likely to cause injuries.
As Dave pointed out, transgenderism is a documented phenomenon. Up to 2% of people are not cis-gendered. That means it is not arbitrary or illogical to look for alternatives to "he" and "she". Nor would I say that people in this group don't deserve consideration, given that people in that group may find relief in not having their gender misrepresented.
On the other hand, there are those who feel society should accommodate for this by dropping all assumptions about the gender of strangers. Basing pronouns off of someone's name, physique, dress etc. is to be avoided, or at least worthy of an apology if one gets it wrong. Introductions should start with proclaiming your preferred pronouns, and so on. IMHO that doesn't make sense. Despite the incredible variety of human physique, our brains are extremely adept at instantly assessing people's sex. That, in combination with the fact that 98% of people are cis-gendered, mean it's ludicrous to complicate communication about strangers for fear of misgendering one in 50 times.
In other word, if someone tells you their preferred pronouns, use them. Otherwise, trust people's instincts and don't make a fuss when they get it wrong.