Pokemon Rebel Clash is set to release in early May. Whether or not that holds is yet to be seen, but one big question about the set is whether or not Charizard will make it in.
Historically, sets with Charizard in them have sold well. This includes, for the Sun & Moon era, Burning Shadows, Unbroken Bonds, and the infamous Hidden Fates. Even Cosmic Eclipse's Charizard & Braixen GX held high value early-on, though it dropped over time.
With Sword & Shield introducing Gigantamax Pokemon, and Charizard being one of them, it was inevitable that they would make a card. Again, whether or not it is in Rebel Clash, a future set, or a box set remains to be seen, but expect this card to be a great long-term investment or a nice piece of a 'zard collection.