Last year a group of authors put online a paper, titled "XYZ". The paper "XYZ" contain part I and part II.
Later the authors deleted the old file. They published a new paper called "ABC" in a good journal. On paper ABC they explicitly state that "ABC" supersedes "XYZ".
In ABC, the old results in part II is completely removed. I checked their part II and their results were mistaken but some calculations and deduction are correct.
Very recently, I find out that one of my submitted paper is closely related to their deleted part II, but is unrelated to their new ABC. Since ABC and my paper deal with different research topics, I did not read either ABC or XYZ until very recently. XYZ is still available to the public in an old repository.
Does their superseded paper established the priority for them or I can still claim the priority? Do I need to talk to that group?