1) There are many greek-latin hybrid words in biology (hepatocyte, neurotransmitter, gastrointestinal...).

2) Xenogenesis is a word that already existed before the publication of the article and using the same world could have been confusing: https://pubmed.ncbi.nlm.nih.gov/17901077/.

3) Given than we're talking about a species that lay another species in order to create hybrids, using a word that is ethymologically hybrid sounds like a perfect fit.