Indeed. Hellfire Peninsula was supposed to be an endgame, level 58-60 zone in classic WoW that continued the steps of Warcraft 3 (Kael'thas, Illidan and Vashj invading it). To reach it, you most likely had to walk through the Dark Portal.

It's a very cool zone and had a very similar skybox to the current one in Hellfire (except it was of less quality than now -it was a crimson skyline with a red sun and above it a green, misty line that went across the skyline; you can see this in WoW Model Viewer), and it wasn't floating in the nether, it had water! Like the old Draenor before it got shattered.

In fact, the Pools of Aggonar that you can see in the video originated in this old Outland, and then took it for the new Hellfire in the Burning Crusade. Sadly, since it was in the middle of development, you can't see any Hellfire Citadel or anything; it's just bland red terrain where it's stupposed to be.

The zone resembled the Warcraft 3 Hellfire Peninsula much more than now, it was more red with crimson fog in the sky, less dark, the floating rocks actually had the same models used in Warcraft 3. The draenic huts you see, for example, in Nagrand or Zangarmarsh, were used here too. There were a few doodads like black rocks with red stripes going upward that thrust up from the ground that can be seen in concept art for Hellfire.

The blade throwers for orcs and the huge tanks with tires and cannons for humans were there too since the beginning! These models, therefore, date from 2002-2003, and were reused when they decided to scrap this old Hellfire for bigger plans -The Burning Crusade!-

In short, it resembled the Warcraft 3 outland a lot more than now. And there were no signs of Illidan or Kael in there, it was all the Alliance Expedition remains (what would now be Honor Hold) and an orcish outpost that, in my opinion, looked more demonic than the Thrallmar of today.