Here Chaucer lumps two women together because they were treated shamefully by the same man, Jason. Chaucer again refers his audience to his source: "Lat hym go rede Argonautycon, / For he wole telle a tale long ynogh" (1457-1458). Avoiding mention of the Lemnian women's slaughter of all the men on the island, the narrator instead beefs up the role of Hercules, pal of Jason, who essentially though subtly challenges Hypsipyle to love Jason. After some unconvincing righteous indignation at possible cads in his audience (1552ff), Chaucer reports that Jason did marry Hypsipyle and had two kids with her -- so it's a pretty long time for a joke. He does leave her, and Hypsipyle writes him a letter "Which were to longe" to bother with here.
The Medea section ends with an identical shirking:
Wel can Ovyde hire letter in vers endyte,
Which were as now to long for me to wryte.
(1678-1679)
Medea is best known for being an uncontrolled murderess in league with Hecate. Naturally there's no mention here of her brother being hacked up and his pieces scattered on the waters so that she and Jason can make their escape from her father. There's no mention of how she avenged herself on Jason, by murdering their own two kids. Nor do we hear about the poisoned cloak and tiara she sent Jason's later fiancée which ate into her flesh and killed that girl's father as well, nor the time Medea made daddy stew out of Jason's uncle. So she's rather a stretch for the list of "good women" which now seems to amount simply to being jerked around by bad men.