A Little Help From Your Family
The gods know how Jon reacts to finding out the truth, and so in a bid to try and stop the impending rift between the last two members of House Targaryen, they send the Rogue Prince and the Realm's Delight forward in time to help their grandchildren set things right.
Daemon has no shame in making sure everyone knows he loves his niece Rhaenyra. He'll show his grandson that being a Targaryen means you're more than allowed to fall in love with your aunt, in fact, you had better.
Rhaenyra knows she's the heir to the Iron Throne. She also knows she loves her uncle Daemon. She'll make sure Daenerys is prepared to be the Queen she was always meant to be while also ensuring that her granddaughter has her nephew's heart and soul in the palm of her hands.
Because what is family good for if they don't help you out when things start going wrong?