Looking at the code that runs existing warp mods (like
this for example), it doesn't look so hard. A naive implementation could just take a list of existing warps that the target player has access to and picks a random element, printing the name of the warp it chose as you arrived so you could find it again.
A slightly nicer version could make a better experience with things like only considering main builds, but that would be a big administrative effort to decide which warps are "main" and a nice way to store the metadata of what is/isn't alongside the warp list.
But I don't actually know which warp mod WC uses, so the mods/coders would know better.