Niek Hilkmann writes about all that in "The Greatest Recursive Disco Medley in The World", referencing Retromania upfront:
"Two years after Reynolds published his stream of thought, Daft Punk released an album that almost seems to be tailor-made to illustrate his ideas".
And it's true, if I'd written Retromania for 2014 publication, I could have dedicated a whole chapter just to Random Access Memories.
Hilkmann writes about the retro traits within disco itself,
"In 1978 a Dutch popstar called Theo Vaness decided to release his first disco record. It was called ‘Back To Music’. The record starts with the sound of machines rattling and beeping in the background while a voice declares:
This is the year 2501.
Our world is no longer a place where you can dream of the future.
Only of the past.
We use our time machine now and then to go back to nature, back to music.
After this a disco beat starts thumping and a countdown commences. Year after year passes, until the listener reach 1978, the year ‘Back To Music’ was made. The journey through time is far from over, as Theo Vaness starts singing a medley of Beatles songs and other popular hits from the fifties, sixties en seventies. After a couple of minutes the trip reaches an euphoric climax and the listener is safely transported back to 2501, the year where there is no place to dream about the future and people go back in time to experience music. The story that ‘Back to Music’ tells can be seen as a mere piece of science fiction, but Vaness’ thoughts on how music might be perceived in the future isn’t so far off from Reynolds stream of thought, or what Daft Punk illustrates on ‘Random Access Memories’.
He also discusses the ‘Stars On 45’ golden-oldie medleys made by Jaap Eggermont for Van Kooten of Red Bullet Productions
"These bootleg disco records feature soundalikes who sing bit parts of popular songs and artists. For instance, ‘the greatest rock and roll band of the world’ features seventeen Rolling Stones songs accompanied by a relentless disco drumbeat that goes on and on and on. The beat regulates and unifies the songs and takes them out of their context. The records were scorned by critics, but made a lot of money. The first record, comprising of Beatles hits, sold over a million copies in America and went gold in several countries. In essence, ‘Stars On 45’ appropriated existing melodies to a contemporary sound, much like Theo Vaness did. However, like Daft Punk, there is a recursive mechanism at work. The lengths the producers went through to make the records sound ‘alike’ are quite extravagant compared to today’s standards. It takes some skill to distinguish a ‘Stars On 45’ sample from a snippet of the real deal. There surely is some art involved in making inconspicuous covers, but with current sampling technology this whole process has become so easy that the process, or even ‘recognition of the ambition’ of sounding alike is not that interesting anymore. This makes the Stars on 45 a little anonymous nowadays and it’s hard to feel any form of nostalgia towards the records."
Plenty of other examples of retro tendencies in disco culture, from Dr. Buzzard's Original Savannah Band to (as someone pointed out here in the comments not so long ago) the glitterball itself, which harks back to the 1930s and the era of dance marathons as in They Shoot Horses Don't They.... and for that matter I Remember Yesterday, the Donna Summer album on which "I Feel Love" appeared, which was conceived by Moroder as a conceptually linked series of songs about different eras (1940s, Fifties, etc) culminating in a song about the future.