GPU die can take a buttload of voltage, but if the initial 'spike' required to turn the GPU on was too high for the PCI-E slot to handle it could in theory damage mobo power delivery. Depends on how robust the motherboard's mosfets are really, obviously CPU power delivery tends to be beefed up to all hell for supporting CPUs with beefy TDPs, but the PCI-E slots are only intended to handle a wattage of something like 70W before it hits a limiter and the PSU has to drive any additional power the card wants.
I'm no engineer, but i've not seen ESD kill a board so outright so quickly, I've seen it stop machines POSTing because of DRAM death or the like, but not fully bricked power delivery
This theory is born of watching one of my fav techtubers accidentally murder a CPU by rebooting it with the Vcore set to around 1.6v - the 'spike' above the running level to turn it on totally cooked it.