It looks like ASRock has spilled the beans on their upcoming Z490 and H470 motherboards as data files for these boards were found in the program files of their Polychrome Sync RGB software. When it comes to the Z490 chipset it looks like ASRock will have 9 motherboards which include the ASRock Z490 AQUA, Phantom Gaming 4, Phantom Gaming 4 SR, Phantom Gaming 6, Pro4, Steel Legend, Taichi, Z490M ITX AC, and Z490M Pro4.
For H470 ASRock only has two boards listed, which are the H470 Steel Legend and H470M ITX AC. Another interesting listing found in the files is the W480 Creator. The W480 chipset appears to be meant for workstation solutions.