Do you know how to get out of the rain, are do you know when it's raining?
Most all vehicles that have a multiple engine platform, have a general wiring harness. That means there are wires that are not used if you have a different motor platform. If you look inside your computer you will find the same thing unused sockets and wire's .
Yes, but this is the only time I've ever seen raw wire ends left exposed to the elements in clear view in an engine bay.
Toyota's solution? Put a connector there, then put a dummy mating connector on the other side so the wiring there does not corrode. This is also the solution for just about everyone in the world - except the American makers.
They do NOT just leave raw wire ends dangling in space.