@5words - I do think it's possible that the AAMC is experimenting with the content and it's possible they've decided to try out significantly longer passages than before. I will say that they've written in numerous places (
including here) that the passages will be 500 to 600 words (and the far, far majority of passages in their released practice materials are 500 to 600 words). I think it's unlikely there's been any huge change. At the average reading rate of 200 words per minute, if it really took 8 minutes to read straight through without lots of pauses or rereading, that would mean its a 1,600 word passage. I find that highly unlikely. I suspect that they increased the passage length by maybe 100 to 150 words (over 9 passages being 1,350 words extra (1,350 words /200 words/ minute) that's a total of 6 minutes extra spent on reading. That's not really too bad or too extreme. The far majority of time on the CARS is not spent on reading, but on answering the questions. Whether or not they're 25% longer isn't a radical shift.
With that said, remember that your MCAT scaled score is relative to the performance of everyone who took the same test on the same day that you took your test. So while the passages might have been longer on 1/19, everyone faced the same disadvantage so it really shouldn't have a major effect on your scaled score. I do understand why this is upsetting, but I don't think this is going to have a major impact on the CARS section. We'll have to wait and see. If there are a number of more test dates that report this and we see a major dip in CARS scores in comparison to early test dates, then it might be time to re-evaluate the way we're preparing for the CARS. Until then, I think your best way to prepare is to use the AAMC released materials and continue to work on getting through reading the passages as efficiently as you can. Take a look at the below spreadsheet and it's easy to see that the AAMC materials, overall, are very representative of the actual test.
I do think it's really crappy of them to not be consistent though, so I definitely understand the frustration. Also, I do think post-test jitters is a thing. Most people think they did terrible the day after their exam....the far majority of people. I was certain for the first three days after my test date that I was going to have to retake and I ended up scoring in the 99th percentile. It's a major mind game. I think we shouldn't worry about this too much until we know more.