One of the things Daedalic promised in The Lord of the Rings: Gollum is that Gollum won’t be alone.
That might seem like an odd choice at first.
Gollum tends to steal from and/or murder the folks he encounters, after all.
We know Daedalic will introduce at least one new character to Tolkien’s world early on, a fellow prisoner in Mordor.
It’s not clear what will happen to him, or if Gollum happens to him, but we’re not too interested in the new characters right now.
We’re interested in the cameos.
The lord of Morder doesn’t have much reason to interact with Gollum after extracting the Ring’s whereabouts - so that means we need to see him in Mordor before Gollum escapes.
Sauron undoubtedly has plenty of torture methods at his disposal, but seeing Gollum on the rack or having pokers shoved in his eyes is just misery pandering.
Seeing Sauron peel Gollum’s defenses back and scour his soul with the all-seeing Eye would justify Gollum’s terror and the tendency of his dark side to take over in times of stress.
This one’s a given, admittedly, but we still want to witness Gandalf meet Gollum.
We know the two cross paths thanks to chapter two in Fellowship of the Ring, and it’s where Gandalf develops his pity for the creature.
We need to see that, though, see the differences in interrogation methods Gandalf uses compared to Sauron and see how, at that point, Gollum is beyond redemption no matter the kindness shown.
Part of Gollum’s story is a bit murky, namely, the question of how he found the Fellowship to begin with. Yes, the Ring is calling to him, but Middle Earth is big, and Gollum is just one shriveled shell of a creature. It’s not as if Bilbo had radar sensor knowing where exactly Frodo was.
But Saruman did know. If Orcs of some variety helped Gollum escape the Greenwood, there’s every reason to think they could have been working under Saruman.
Maybe this seems a bit tacky, but bear with us. Gollum spent plenty of time in the Greenwood, and we have no good reason to care about Thranduil.
He’s a pain in The Hobbit and practically nonexistent in Lord of the Rings. Having some kind of interaction between the two wouldn’t make much sense contextually.
However, Gollum could witness the conflict that drives Legolas out of his father’s home and into the Fellowship, one important part of the trilogy’s lore that never gets much attention.
If Gollum trekked through the Greenwood, then he surely came across Beorn at some point, or Grimbeorn depending on when Beorn actually died. In The Hobbit, Beorn’s like a giant Tom Bombadill, someone who knows everything that goes on in his domain.
And it’d be pretty hard for a being like that or his offspring not to realize a creature such as Gollum was lurking about.
The Beornings suffer an attack from Sauron’s forces while Frodo is in Lothlorien, and that’s basically the last we hear about them.
Perhaps Gollum inadvertently acted as a spy, leading Sauron’s scouts to the Beornings and precipitating the Dark Lord’s assault later.