It is extremely early for it, but they indeed announced that a preload should be possible right now. If OP's preload isn't working it's worth figuring out why now, so that if the issue maintains later it's not too late to have the game ready to go.
Last I heard, it would be ready "this week". Since the game won't be out for a few weeks yet, I think you can be patient and wait for the preload. No matter how slow you internet is, you will still be ready in time.