I think the matter is if random distribution is what is documented, no one will raise an eyebrows. I believe the Heroku claimed intelligent routing based on server loads to route traffic to idle servers. That threw people off.

Not only that, but they charged a premium based on their false claims. I'm surprised it took this long for legal rumblings to come around.

I dont know, but I would assume it has to deal with the fact you can't predict how long a job will take to complete, and a random selection would have more resources-more free-more often, verses FIFO where a group of really large tasks could halt everything.

And what if they turned the whole thing into a request queue and workers get the "messages" as they become available? To ensure there are no timeouts, they could define a max time a request may stay in the queue, and then take it out and handle it with emergency workers or kill it?

That's exactly correct. Given jobs cleared out quick, that wouldn't necessarily be the case.

I think you are supposed to take least busy of two random nodes.