To tell you the truth, I haven't noticed. I've spent so much time on the seasonal time trials enjoying the new physics engines that the days and weeks have flown by.
I've driven most of the career mode tracks so many times that most of the "newbie" challenge that I once felt are pretty much gone except maybe Fuji and the one at Nurburg, so if I was concerned about it in the first place, I'd probably say "yeah, it is", because that "new track" portion of the challenge is gone. I'm not saying I'm "pro", but they're all mostly very familiar now, so many of the challenges associated with the unfamiliar are gone. Shrug. It's a drag but not possible to stop without forgetting all the laps you've put in at (insert track name)
Edit: but imo it's ok. GT6 is only going to get better, challenging A-spec or no.