I think it was Andrew-Lee in an interview who commented about thw writers taking the opportunity to change the things that didn't work from S1. Now you mention it, I suspect you're right about it meaning they never intend to go back to the Claudia timeline.

I'd love to see Abby have more to do in S3. In S1 she was obviously there as the animal expert, but in S2 pretty much all the creatures were big nasty predators, so it was a case of shooting them from a long way off rather than handling them, so Abby had sod all to do really apart from those nice scenes wirh the mammoth towards the end.