@spook Time walk is a funny card in this deck. It can be the best or the worst card in some situations. I for instance don't play it, so I'll tell you as one of those weird people that don't play this power card. Everything I'll say is from my experience (I didn't get any insights from other people to decide it) and as there are other few people that also don't run it, may be the right reasons.
The problem about timewalk is the beginning of the game with bazaar. It's a 2 mana card that doesn't do anything if not in the right conditions (with pressure or more mana/things to do in hand). Also, it doesn't do anything in the GY. And it's a 2 mana non-creature card.
When you are bazaaring, you are essentially losing card advantage. You lose at least a turn of land drop and some card advantage, which should be compensated with explosiveness. And sometimes, it's not. Sometimes it depends on leaving some creature in hand to trigger vengevine, and when you are on turn 2 or 3 with 2 mana available and still no vengevine triggered, you have to leave it to hardcast some creatures. And when you do that you will usually have 1, 2 or no card left in hand. In order to do that, you would need to discard time walk, which would have done nothing at all in the game.
In my experience, when you play non-creature 2 drops you expect it to have an immediate impact, most likely a very strong impact (such as stony silence, thorn, and obviously survival). When you are playing a deck with thalia, thorn, bazaar, 14 mana-producing lands (which in this spot start being played from turn 2), moxen and spirit guide, you should really only play non-creature expensive spells when it has a strong impact in the game. Obviously you play survival which fits in a "expensive non-creature spell", but that's a part of the game plan, the 5-8 slots for enabler in the deck. And even survival itself, when you start the game with bazaar, it's usually not really good, when you get to play it as you need some amount of green mana for it to be good and starting the game with bazaar usually leave you in a green-mana-shortage for the rest of the game.
Obviously, I may be wrong. But when I played time walk it was always bad (I played it for 2 or 3 leagues only, so I don't mean to say it's always bad). And when I stopped playing time walk, I sometimes missed it, but mostly for not drawing it in the late game when I had already some board presence. I never missed it on the early game, which IMO is the most sensitive part of the game, where you really define if you will or not win the game.