Some conferences are in locations with restricted accommodation facilities, and if you don’t specify a roommate, you are paired with someone of your gender.

So that’s why the gender might be needed.

As far as the preferred pronouns are concerned, I see them as something with heavy political connotations. No one who is not hard left believes in the necessity of the xir pronoun, and of course there are trans people also among the right!

So, to me it’s completely acceptable that something so controversial is not included.