I was actually just thinking about this potential. Kinda ironic. I asked myself, "What if I HAD gone left just outside the nautiloid as opposed to right?"
Answer? I would not have met Gale, not would I have gone to the crypt, and I might even miss Lae'zel.
How does that impact the game? Not much, actually. 2 less companions, maybe, and you miss the death safety net which is Withers.
I've used Withers maybe once since EA began. Not a huge loss. Are there story elements you miss? Not much. Maybe a few hints at the overall story. Nothing huge. Any cool items? A spear you may or may not use.
So, overall, no big loss. It's actually not a very important part of the game.
