Well yes. They're not even being subtle about it any more. The moment he saw L'Rell and started having visions was a dead giveaway. The conversation in the brig confirmed it beyond reasonable doubt. There's maybe a fraction of a percent chance that it's some grand misdirection on the part of the writers. So yeah, at this point, I don't really see how Tyler could NOT be Voq.Tyler is Voq

So are we to assume that Discovery has jumped to a different quadrant (like the Gamma quadrant) and hence why there was no spore drives or mention of it in other trek series?
It's almost certainly the mirror universe, with the Terran Empire and whatnot.Nah, they were banging on that much about alternative dimensions in that ep that I'd be surprised if it wasn't (plus with the jump not going as normal). The writers aren't exactly.....subtle.
There was that ending of episode ep5 “Choose Your Pain.”, where Lt. Stamets mirror image stood fixed as he left the room?I'm sure I read somewhere that discovery will visit the mirror universe so no doubt that's where they are
Maybe they were already in a parallel universe and now they've jumped to the prime universe.....
Well yes. They're not even being subtle about it any more. The moment he saw L'Rell and started having visions was a dead giveaway. The conversation in the brig confirmed it beyond reasonable doubt. There's maybe a fraction of a percent chance that it's some grand misdirection on the part of the writers. So yeah, at this point, I don't really see how Tyler could NOT be Voq.
On another topic, I'm super happy they seem to be moving away from the "Klingons speaking Klingon 100% of the time" thing. The actors, when speaking English, are actually able to... you know... act. And emote. And all that good stuff.

No, the Federation never existed in the mirror Universe.