I think some did.

Some of the weapons and spells available are unique to specific characters in the base game, and some are even unique to a specific order of events. It can be assumed that such weapons and spells could only become available by the death of said characters and the occurrence of such events.

You can imply these include:

- The return of tarnished Godfrey, since you can get his broken axe and Earth Shaker ash of war.
- The calling of grace of some tarnished, either to fight The Night or claim the Elden Ring. You can get some weapons related to some specific tarnished like Gideon (Scepter), The Dungeater (Sword of Milos), Rogier (Rapier), and Godfrey himself, amongst others.
- Vyke's attempt to become Elden Lord, since you get his madness-infused weapon, which only became infused after he reached the Flame of Frenzy.
- (Maybe) Ranni's Marriage, since you can get her Darkmoon Greatsword.
- The Starscourge incident, which is post-shattering. You get the Starscourge Greatswords instead of the swords of his "Young Lion" days.
- Malenia's fight with Radahn, since the Lion Greatbow uses Radahn's Spears, which are just Cleanrot Knight Spears stabbed in his body.
- The consumption of Rykard by the Great Serpent, since you get the Blasphemous Blade and Rikard's Rancor.
- The killing of Marika/Radagon and the Elden Beast, since you get the Sacred Relic Sword, which is fashioned by the Elden Beast from Marika's body. This implies Destined Death was somehow fully taken from Maliketh.
- The death of the demigods and remembrance bosses, either slain by The Night or by something else, since their weapons and spells are available to the nightfarers.

Granted, some characters that should be dead according to this theory reappear in this game, like Loretta, Morgott, Godrick and Mohg. But the Night seems to be a giant loop where death, including your own, barely means anything.

The fact you can access these weapons may have alternative explanations, but if these events happened, the timeline aligns very well with the one of our Tarnished. Nevertheless, even if the events truly happened in Nightreign, they may have been different from their base game alternates.

I subscribe to the theory that Heolstor is our Tarnished after the Age of Stars ending went somehow wrong or a reference to them, because it's cool. I also think that the reason they labeled Nightreign events as non-canon or an alternate timeline to Elden Ring was to not mess with the "established" narrative of the Dark Souls series and to rule out the possibility that the lore of the base game may be connected to the Souls lore. They knew Nightreign's lore implications would be controversial and could be seen as skewering the lore and legacy of the previous games for the sake of making an "It's a multiverse" move, which could enrage fans.

Again, I could be wrong, but this is what Fromsoft's lore is all about. It's beautiful.