That doesn't really answer the question, as it being historical narrative does not mean that it is history. Gordon Wenham notes that whilst Gen. 1:1-2:4a is not poetry it is not your average historical narrative either, rather it is elevated prose. Wenham writes:
Extrabiblical creation stories from the ancient Near East are usually poetic, but Gen 1 is not typical Hebrew poetry. Indeed, some writers endeavoring to underline that Gen 1 is pure priestly theology insist that it is not poetry at all
.On the other hand, Gen 1 is not normal Hebrew prose either; its syntax is distinctively different from narrative prose. Cassuto, Loretz and Kselman have all pointed to poetic bicola or tricola in Gen 1, while admitting that most of the material is prose. It is possible that these poetic fragments go back to an earlier form of the creation account, though, as Cassuto observes, it is simpler to suppose
the special importance of the subject led to an exaltation of style approaching the level of poetry. Gen 1 is unique in the Old Testament
it is elevated prose, not pure poetry
in its present form it is a careful literary composition introducing the succeding narratives.