im pretty confused on this

[Sonic The Hedgehog]

so ive played sonic O'6 and it practically erased itself from the timeline.

so HOW did silver become friends with sonic again after the O'6 timeline was erased?

(since i cant find an O'6 port for PC this was the next best thing(i am aware of project O'6)

[Devsman]

They ran into each other at the same bar and after some drinks they realized they really had a lot in common

[ChimeraS]

It's debatable whether or not this game is canon but look at sonic rivals for the psp. it features sonic and silver reintroducing themselves at the beginning of the game. That's the only answer I have.

[Susie]

As ChimeraS said, the next game Silver appeared in is Sonic Rivals for the PSP, where Sonic and Silver meet again.
But it's not clear if Sonic Team counts Rivals as canon, as Sonic Rivals 1 & 2 are not listed games on the official Sonic Channel website.

Some things to note, though:

1) Silver appears in the multiplayer mode for Sonic & the Secret Rings, Sonic Riders Zero Gravity as a racer, and Mario & Sonic at the Olympic Winter Games as a contender.

2) Silver also appears in the DS version of Sonic Colors as an NPC and seems to know Sonic as a friend already.

All of the games I mentioned are before Sonic Generations, so it's possible that Sonic & Silver reintroduced themselves at some point off-screen.

[GlaceonChireiden]

Sonic 06 happened and all the characters remember it, but the events within it never technically happened.
Think of it like a collective dream they all had. They all remember the story beats, but none of it really "happened"

Something to note about Rivals, it actually used to be on the sonic channel website for silvers bio until semi-recently when it was scrubbed. His 06 incarnation is all that's there, so it's safe to assume 06 silver is the canon silver.