mordred through time (movies, tv shows, opera and musicals)
Part 2: From 1982 to 2002
Other Parts: Part 1: From 1949 to 1981 -> here Part 3: From 2002 to 2010 Part 4: From 2014 to 2017 Part 5: From 2018 to 2023
EDIT: There is a mistake in the video, Blind Guardian's Mordred's song was released in 1995 not 1989, so I corrected it in the description.
Complete list of part 2 media with extra information and some of my thoughs regarding the evolution of Mordred’s role is under cut.
We left part 1 with Mordred appearing only as a generic villain not related to Arthur until 1960 where White's novel is adapted into a musical. The musical follows the novel enough to introduce Mordred as Arthur's incestuous son with Morgause. Since then the "son" element has been kept in almost every single adaptation. We also have the first tv iteration of Mordred as Morgana's son instead of Morgause: Excalibur 1981.
This is not only the first time we see Morgana as his mother on tv, but also one of the first time ever. I made a list of the evolution of Mordred's mother in novels here.
You can see Morgause is pretty constant until 1980-1982. I have no idea what happened in those years but for the first time we have the 1980 novel "Firelord" by Parke Godwin itroducing Morgana as Mordred's mother instead of Morgause (in this case Morgause is completely eliminated). The 1981's movie Excalibur does something similar (Morgause is eliminated and Morgana absorbs her role), and I am pretty sure it could not have been influenced by "Firelord", given the two events happened so close in time (and less than a year is not usually sufficient to write and produce a movie). In 1982 Marion Zimmer Bradley published "The Mists of Avalon" which does something similar to Catherine Christian's "Pendragon": Morgause is still officially Mordred's mother by adoption.
From this point onwards you will see that Morgause ends up completely eliminated in her role as Mordred's mother from future movies and tv shows.
Full list for part 2 and more info: