What if Baelon (Viserys/Aemmas son) lives in your universe? Would Rhaenyra still be heir? Is Baelon a rival for the other targboys? I am smelling a love-triangle hehe <3
Viserys named Rhaenyra as heir because he wanted Daemon away from the throne. If Baelon lives, then Viserys never names Rhaenyra as heir. Baelon is the heir from the moment he's born.
Viserys could still marry Alicent, because it's risky having only one daughter and one son in the line of succession. Also, if I wrote a fic with this premise, I would make it so that Baelon, although he survives childhood, has been sickly for his entire life. That adds another impetus for Viserys to remarry and have more kids.
If we're wanting a love triangle, then:
Viserys marries Alicent. They have Aegon, Helaena, Aemond, and Daeron, just like in canon. Aegon is second-in-line behind Baelon, who is the firstborn son.
Rhaenyra marries Laenor, for similar reasons as in canon. It's an excellent match on paper, and Viserys needs to pacify the Velaryons somehow for snubbing Laena. Rhaenyra isn't the heir in this AU, but as the only princess of the Crown, she's still a desirable marital prospect.
Rhaenyra and Laenor have Jace, Luce, and Joff. Viserys betroths Baelon and Jace, so he can a) further pacify the Velaryons with a future queen and b) solidify Baelon's status as heir by giving him a Valyrian bride. Since Baelon is very sickly, he doesn't really impress anyone as heir, so Viserys finds it important to bolster Baelon's image. Baelon would get a cradle egg, but his siblings are denied eggs because Viserys doesn't want them showing up their big brother.
Jace knows it's her duty to marry Baelon, but it's only her duty. Baelon is bedridden most of the time, and she expects she'll be more of a caretaker than a wife.
Meanwhile you have Aegon, who is glad not to be the heir…but he's jealous that Baelon gets to marry Jace. There's a big rivalry between Baelon and Aegon (Baelon is jealous that Aegon is so healthy and full of life), which might mean Aegon is closer to Aemond in this AU.
This could result in an alternative Dance of the Dragons, where it's two brothers fighting for the same woman. (Bloodraven/ Shiera/ Bittersteel triangle?) Or maybe Aegon elopes with Jace just before she's supposed to marry Baelon. Or maybe Jace marries Baelon, but she's having an affair with Aegon.
What a spicy scenario! It's giving me a lot of food for thought.
