Yeah that's what I was thinking. People hardly ever disconnect their power cables let alone this new detachable dock design. Gold is literally used on a lot of computer components such as RAM and you don't see it being a problem there. Why? Because people also don't repeatedly reseat their RAM. Using Gold on that connector is a lot less of a failure point than bare copper. I think the "server-grade" is more along the lines of pointing towards it's a similar (if not identical) design that a lot of servers use with their card-edge connector. Especially for hot-swappable PSUs. Which hardly ever fail.
In addition to all of that. The gold plated fingers for any of those connectors be it RAM, PSU, PCIe or whatever else isn't pure 24k gold anyway. It is indeed mixed with something else to make it harder such as cobalt or nickel anyway. It even says so in the name, 30µ which is designed for repeated mate cycles.