Honestly, I love this album, because its sounds like you would have naturally expected if they released something shortly after Black, but never really did.
We all know with Load/Reload, they were leaving thrash/metal aside chasing grunge/alt hard rock trends, with St Anger- some kind of misguided attempt at appealing nu-metal fans/hardcore kids, Death Magnetic and Hardwired were the band trying their best to prove they can make a Master of Puppets/Justice like album again, but just not meeting that challenge- they will never get the feeling again of being 20-somethings in the 80s making pioneering thrash metal.
72 seasons kind of just pulls in all of their experience- the sound is kind of black, but with dashes of the more experimental pre-black albums, and a little bit of Load-era bluesy-ness too. They are still a heavy band, but they aren't pushing it too hard anymore. They are just making a solid-post black- Metallica album and it feels more natural than it has in decades.