Alleged NVIDIA GeForce RTX 3050 8GB Die Swap Brings Power Consumption Way Down

The answer, according to Igor's Lab, is that NVIDIA planned all along to bring out an RTX 3050 based not on GA106-150, but instead on the GA107 GPU. GA107 isn't a new chip; it's already been used in the mobile GeForce RTX 3050 and 3050 Ti, as well as in the MX570, the A2 accelerator, and confusingly, the GeForce RTX 2050.
As you've surely assumed by now, the GA107 GPU only comes with eight PCIe lanes. This makes the die significantly smaller, and probably has an extremely marginal impact on its performance (compared to a full x16 bus), at least when used on a platform with PCIe 4.0 support.

Even if you're not into overclocking, the smaller die should still mean less power consumed, and less heat dumped into your case. Unfortunately, it's possible that it will be difficult to tell from the outside which cards come with the salvaged GA106 GPU and which cards use the smaller GA107. We'll have to see if vendors make separate SKUs for the two GPUs.