It did, he warped his entire crew out to plan his next move and has Ahab setting on AXIS as one of his back-up plans. Arno and Mayday also seemed to be scared of Kang that they fought the Heroes because they didn't think Kang could be challenged. They seem to have made the smart choice at the time seeing as how easily he warped them all out so crossing him would have ended badly for them as there's no way the 616 Heroes could save them from Kang's wrath if they had betrayed Kang.
I don't think RR would want Spiderverse to interfere with the Kang story he's trying to tell.
You assume she would be a part of Spider-Verse. She's not an Alternate Peter and she goes by Venom and she's a Mutant. So Morlun may ignore her completely since he has more important things to do than go to war with Kang over someone who isn't even tied to the web. Heck his family may ignore MC2 Spider-Girl and only care about killing MC2 Peter Parker.