From earlier in the article they say this testing is with ultra settings, and for a modern game it would be expected that they're creating content that shows off well at 4k resolution and easily push past what 8GB VRAM can contain. The PCIe5 system is still affected, it's just affected less. There's probably tricks they can use to stream detail levels in/out of VRAM depending on how objects are displayed on screen (like the early direct storage+sampler feedback demos), but that's more work to do effectively and would still put pressure on PCIe and storage being fast enough to keep up.

I'd say it comes down to players picking appropriate settings for their system, and it being good if the developer can can provide the information on the consequences of different settings (showing VRAM usage), or a warning if you're below their required/recommended system.