Because Bungie hates ROI for some reason and essentially retconned anything from it out of D2. It was so weird the first Iron Banner/first time Saladin was in the tower for D2 and he acted like he didn't even know who we were...like we literally spent an entire expansion with him and now we're just another run of the mill guardian. ROI was one of my favorite expansions and it drives me crazy how much Bungie ignores it.

So think about it like this: Bungie made Rise of Iron way back in D1 right? Then they decided they hated it, and the story bits that could lead to future stories from it. As a result they quite simply thought "What if we just pretend it never happened?". It is the reason they have: Not brought forth the last raid from D1 into D2(Siva raid) Cancelled the plans to put the rest of the cosmodrome in D2(Siva related area in D1) Did not use the Siva version of Devils Lair strike(Siva redo when RoI came out) Dropped lady Efrideet as a character and don't have her run the iron banner event cause Saladin is cabal property now, but sneaks off to do this i guess? And that brings us to today.

My T is an Iron Lord. That is his identity. His (gilded) Seal identifies him as such…it always has…and always will. He climbed the mountain…lit the fires…defeated the Siva threat…was ‘knighted’ as an Iron Lord…earned the ‘Young Wolf’ emblem…saved the world - again! 😎 That is all. Ease springs! ✅

There is also Lady Efrideet She may have joined a pacifist Cult(which is a lazy way to write her out of the story) bit she is still an Iron Lord Also to your point about us being an Iron Lord, we are not part of the story , we are just a plot device so anything pertaining to us isn't canon Like Miisrax not recognizing us even though we spared him in the Enemy of my Enemy adventure on Titan

Guess we're also going to forget that Efrideet showed up in D1.

Honestly, it’s probably a slight(ish) mistake on their part. You are right, at the end of Rise of Iron, Saladin begins the process of recruiting and training a new generation of Iron Lords. But, even before Rise of Iron, Saladin was referred to as “The last surviving Iron Lord.” This was expanded on later, because, in the lore tabs of D1 (which got a more concrete reveal later) Efrideets survival and whereabouts where rather unknown. So, let’s dive into it all. Firstly, Efrideet. Why is Saladin the last surviving Iron Lord despite Efrideet being alive. This is because Efrideet, before the Siva Crisis, exalted her oath before the Iron Lords would eventually march against the warmind Rasputin and Siva itself. So, since she withdrew herself from the order, she was no longer considered an Iron Lord. So, after the first battle against Siva, Saladin was accurate when referring to himself as the last surviving Iron Lord. But, it goes without saying, there were other guardians present during the days of the Iron Lords; who, more often than not, were associated with the group. To name a few, Shaxx, Drifter, Osiris, Zavala and Etc.. So, being present or just associated did not make you “One of them”. So, that brings us to today. Like you said, after Rise of Iron, a new generation of Iron Lords formed. With that being the case, why is Saladin still referred to as “The Last Surviving Iron Lord”? Well, two reasons. Both, somewhat being one reason. One, it’s what he’s been referred to as since his initial appearance. It’s something cool that everyone associates him with. And it ties well into his Iron Banner stuff and you still hear him make references about his “Glory Days” often when you play the Iron Banner. So, it’s just something tied to his character. When new players come in, the short little bios under the vendors give them an idea or something to latch onto towards them. When you read Shaxx and it says “Shaxx runs the crucible, a competition where guardians train each other. Shaxx is the crucible.” And then he proceeds to tell you “Fight, Guardian.” You’re kinda like “Dang. This dude a bit cool.” It’s the same for Saladin. Secondly, his title is still technically accurate. You’re right, Saladin is no longer the “last” Iron Lord. There’s a new generation of Iron Lords out there. But, Saladin does not consider himself “apart of them”. If you pay attention, Saladin does not consider himself a true “Guardian”. He has never referred to himself as a Guardian. It’s the same with Shaxx. Shaxx does not consider himself a “Guardian” to a degree. His name is “Lord Shaxx” not because he was an Iron Lord or even because he hung out with them; he’s Lord Shaxx because he was/Is a Warlord and he still feels like he is. Or at least, that’s a part of his identity he has remained true on. With Saladin, Saladin is the last of his era. The last of an entire generation of heroes. Saladin has witness numerous generations of heroes rise since his time ended, but, no matter what; they will never be “his”. You see? So, yes. There is a new generation of Iron Lords. But, at the end of the day, Saladin is still the last of his generation. The last of the original Iron Lords. The last of the founding Ten. The last one is the big one. He is the last TRUE Iron Lord.

They locked themselves in the vault with Siva. Saladman was conveniently a tad bit late to the party.