The new armor for Tony Stark will be made of vibranium.
The culmination of the MCU is going to come in 2 months with the release of Avengers: Endgame.The grand finale will be about establishing a new team and retiring the old ones.The film will end the story arcs of Iron Man, Captain America, and THOR and set up The New Avenger around them.
Since the MCU veterans are going to be retired/killed off, it is obvious that we will see the best of those characters in order to end their arcs on a high note.If you take the example of Iron Man, we are going to see the best of him or his suit.We have already seen his best suit in the movie.
Tony's best creation to date is theNano-tech suit.If you make sense of it, how is Tony going to upgrade a piece of technology that is already at its peak of advancement?It probably can't get any better.Maybe the weapons of his new suit will become better, but we can't expect anything crazy.
What if the answer is in Wakanda?Any sort of plot convenience that you may require in a story is provided by the unlimited supply of metal that Wakanda brings.To make Tony's armor even better, why not use vibranium?We have already seen that Tony Stark is going to visit Wakanda.
It would make sense for Tony's Mark 85 armor to be made completely out of vibranium.Imagine an Iron Man Mark 85 armor with an insane combination of Vibranium and Nanotech, as seen in Black Panther.Tony could give Thanos a run for his money in the upcoming sequel.
Tony has seen how something works.He might meet Shuri and learn more about the possibilities of vibranium.I bet that the new Iron Man suit will be made here.
Tony can put an upgraded version of material into his suit if he can't upgrade his tech.The Iron Man armour abilities that it never had will be given by that.His armor is going to be stronger than ever, and he will get all the benefits of vibranium.All of us should support Tony's suit.