Final answer:
The key outcome of meiosis II is the production of four unique haploid cells, which are important for genetic diversity in sexual reproduction.
Step-by-step explanation:
The important outcome of meiosis II is the separation of sister chromatids into individual chromosomes, resulting in the formation of four genetically unique haploid cells. During meiosis II, two haploid cells produced from meiosis I undergo cell division without chromosome replication in interkinesis. The division in meiosis II follows steps similar to mitosis but it's critical in ensuring genetic diversity through the creation of unique gametes for sexual reproduction.