Could male and female be a compound antecedent referenced by the plural pronoun “them”?
Yes (the same goes for they)
There is no specific plural pronoun for guys/girls, them and they could refer to a group of guys/girls/guys and girls.
Maria and Andrew called; they can't make it to the party today.
Tell Anna and Blake that they are welcome to come over.
If Jill and Dorian stop by, tell them that I went out.
The male dog and the female cat played together; their owner loves watching them.