black widows fight is a false alarm. that is not mcr5 material. that is a song by legendary hip hop producer and wu-tang clan member RZA for the score of the man with the iron fists (2012). here is my evidence
fig. 1: listing for BLACK WIDOWS FIGHT PT 1 / MY CHEMICAL ROMANCE on publicrecords.copyright.gov. note that it says "Title Appears in Document: 420 & 688 other titles"
fig. 2: the head of the document '420 & 688 other titles'. highlighted is the name of Party 1: Robert Diggs p.k.a. RZA. and then there are 689 song titles below it
fig. 3: a selection of titles in this document (alphabetized; B section), incl. BLACK WIDOWS FIGHT PT 1 and 2
fig. 4: Spotify listing of RZA album Digital Bullet, 2001, containing at least 4 songs on the above list (Brooklyn Babies, Black Widow Pt. 2, Break Break, Bong Bong)
fig. 5: Spotify listing of The Man With the Iron Fists (Original Motion Picture Score) by RZA and Howard Drossin, containing at least 2 songs on the above list, in addition to one track titled "Black Widow's Theme"
fig. 6: excerpt from the wikipedia article for The Man With the Iron Fists
IN SUMMARY: The document that the assumed MCR track BLACK WIDOWS FIGHT was mentioned in is a listing of a significant amount of, if not all of, the works of RZA, including soundtracks and scores. It is possible that MCR was involved in BLACK WIDOWS FIGHT, but that was in 2012, so it has a very low likelihood of being connected to a potential 5th MCR album. If anything, it's an alternate name for Hell Hath No Fury.