First off, I love Daft Punk and I’ve heard all of these song countless times.
But, sorry, I don’t buy it. I am aware of the talking piano effect, but even the wiki page [0] says it’s a vocoder, which is something entirely different.
Similar to other commenters here [1], I don’t hear the pattern described for the octave effect either.
[1] https://open.spotify.com/episode/52t5WCspFuFkow374P88wA (but also Ep 1 and 3).