If you happened to remember the source/link, please send it because I would love to read more on game cinematics development history. The only info similar info I had previously been able to find was on Square Enix [1], but it didn't go into much technical detail.
The two resources you want for 90's gamedev are "Game Developer" magazine, and any materials from "CGDC" (Computer Game Developer's Conference, the previous name of GDC). Both of those have a lot of contemporary info, talks, articles, etc.
There is sadly not a lot of information out there for the early years of cinematics. Your best bet is old issues of "3dArtist" or "Cinefex". They float around on various torrent trackers. Blizzard has hardcovers for most of their franchises with a lot of history and there is also a behind the scenes & cinematics DVD Set for diablo. Square had behind the scenes books for all of the final fantasies prior to 13. There is also a TV documentary "Light&Magic" on Disney about ILM (LucasArts) which is primarily about their feature film vfx work but goes also into some details of "LucasArts" cinematics (mainly early Star Wars Games).
Here is the 1998 CGDC CD as a starting point:
https://archive.org/details/1998_CGDC_Proceedings_CD