The disclosure of a letter from De Vance addressed to Mosen Razai is an indication that Washington has no barriers with whom to negotiate, and its goal is to achieve its terms.
What was leaked, and it was on purpose, is that the nuclear file should be included in the initial talks, that is, the talks to end the war.
It is certain that the cost of other matters has not been disclosed, but it is difficult for Tehran to accept such a step because it undermines its seven conditions paper, derived from the memorandum of understanding, which Trump says was a mistake he made in signing it.
The order of priorities is still dominant, and it is difficult for Tehran to come to terms with nuclear negotiations in light of war. It's a settled matter.
Increased correspondence and negotiations may not mean the possibility of reaching a solution that will satisfy both sides in the foreseeable future, nor does it mean the rejection of renewed war.