Funny thing, I had no idea who she was when I first got into FiM. When people started talking about her as being the person who was designing the latest MLP reboot, I thought maybe Hasbro had run some sort of public contest, and this Lauren person was just some random girl on DA who won. It was sometime after I'd gotten hooked on pone that I found out she'd worked on other stuff before, and I was like, "Oh! She was involved in
those shows...that I never really cared for. Okay."
I love the FiM characters and world she came up with. I liked a fair bit of the over-arching ideas and arcs she had in mind, and thought others were crap. Mixed feelings on her as a person; I appreciate what she's done for the Wildlife Learning Center but otherwise don't care much for her.
That said, I do prefer the first two seasons as a whole, though I don't doubt it was at least partly because it was still new--both in the sense that it was the honeymoon period for me as a viewer, and that the show staff were still fleshing out a lot of what would become canon.
I hate that people still take her word as law, it's like, guys she doesn't work there anymore. Anything she says has no effect on what the writers do know.
The show's based entirely on the foundation of her show bible, and they've said they do their best to follow it. So yeah, what she said absolutely has an effect on what gets churned out. They've also agreed with fans who've pointed out when characters acted off-character.
If you mean what she says after having left as to how she would've pursued a concept, then sure, there's no reason the show would follow those ideas.