AMD and NVIDIA may have new 8 GB cards on the way, albeit versions of ones that they have already released. For one reason or another, an NVIDIA board partner has registered an RTX 3060 with 8 GB of VRAM with the RRA in South Korea, while a retailer claims that people can pre-order desktop PCs with an 8 GB version of the RX 6800.
https://www.notebookcheck.net/New-editions-of-the-AMD-Radeon-RX-6800-and-NVIDIA-GeForce-RTX-3060-emerge-with-8-GB-of-VRAM.522753.0.html