Question - GPU PCIe 4 in a PCIe 3 slot

It clearly states its pcie4 for the gpu at x16 so it will be running at pcie4 all but x4 as the 6500xt is limited to that but working at its max

I don't see a problem with the first 2 cards, but I'm wondering if the 3rd card will work as well? Given that PCIE is twice the bandwidth of

candy bonanza pg slot “PCIe will not be supported on motherboards released prior to the X570, so 400-series and 300-series will have PCIe support,” an AMD

candy palace slot This would be like similar data rate to if a x32 PCIE slot existed, which we can safely say is overkill for gaming scenarios YMMV (eg