The holocaust came of age in the dawn of the information age if you count the radio as information technology, albeit a very one-sided information technology where you had the government giving everyone cheap radios that were only marked to tune to German and Austrian radio stations, unless you dared to go out at night to get an antenna up to receive others. [1]
Just look at how that's evolved into what's now referred to a "talk radio". Only, you have multiple stations available so you can choose your particular firebrand to listen.
This also applies to the Rwandan genocide. A lot of it was perpetrated via mass media, especially radio. But you can also claim that there were Industrialized genocides before the Holocaust, but what sets it apart is just how much it was defined by industrialized processes.
The Gaza Genocide is similar, the use of AI for target selection (or rather generation), the social media campaigns, using drones for killings, etc. We haven’t seen a genocide before which uses information technology to the extent it really defines whole processes of the genocide.
Germany pioneered a lot of modern propaganda techniques in WWII:
The first television broadcast on earth was of Hitler, and his chief propagandist, Goebbles, continues to have significant influence on modern propagandists. For instance, Biden's publicly compared the tactics Trump used in the 2020 "Big Lie" campaign to those of Goebbles. Of course, there was also the Hitler Youth, which was a pretty successful social engineering campaign.
On the computer side of things: IBM mainframes were famously an enabling technology for the holocaust and german war machine.
[1] https://en.wikipedia.org/wiki/Volksempf%C3%A4nger