There is an afterlive in probably every fantasy universe that usually is not meddled too much with because potentially you can do enormous damage to your lore. Shadowlands is a perfect example of that.
Basic insight into core realms? If someone close to us die we just have to talk to our pal Pelagos and ask him to point us in which direction we have to go to take a nice cup of tea with our friend who died yesterday.
Travel to the Shadowlands is, according to the last time that Danuser spoke about it, extremely easy, we just have to cross a portal. I think that he even mentioned as an example a baker visiting his lost ones.
Death is meaningless in WoW until Shadowlands is properly dealt with. Again, we can just go there, grab our pal, and bring him back to the realms of life. Is just that easy. The possibility is there, and if Pelagos do not allow it we only have to use brute force to achieve our objective. One would have expected more mistery or more difficulties, but no, just with brute force, we can bring anyone, probably with his body an all, not an ethereal shape of what he / she was.
Its pathetic.