Well since he didn't re-hire Spaiths or Lindeloff then I would say that he has learned not to use them specifically. He made The Martian since then, and it was really good. However, he also made that Exodus movie which wasn't great.
Ridley is always gonna keep you guessing.The new writing team might throw out a bunch of ideas that make no sense, but Ridley decides to use them like he did in Prometheus. However, he might have gotten his magic back with The Martian being a great movie.
That being said remember when the Star Wars Prequels came out and we didnt like the first one and knew the 2nd one would be better...then we didnt like the 2nd one and knew for sure the 3rd would be better...then the 3rd one came out and while it was the best of the 3 it was pretty underwhelming?
?? Well don't get your hopes up for Covenant. I cant even name one time a movie came out which was considered not good, and the sequel came by the same director and it was all of a sudden amazing. I'm just trying to be realistic. I love the Alien movies, and I really hope Covenant blows everyone away.