implications of test date on bellcurve (to IR or not to IR?)

I just received a notification that my scheduled GMAT (which was planned right before the switch on June 5) has been cancelled, and I'm trying to reschedule. I have a question about how the bell curve works which would really help me make my decision (I will now have to drive 150 miles to take the test before June 5).

I am generally comfortable with standardized tests and haven't studied a great deal for the GMAT (3 practice tests, a bit of work on problem areas), but I'm happy with my practice tests scores (700 range). I have done exactly one IR practice problem -- so I'd be reviewing it from scratch next weekend.

If I take the "new" GMAT right after the IR section launches, my assumption is that everyone will be in the same boat with regards to prep levels -- there just isn't much practice material to study, so we'll all be taking it a bit cold, which is fine with me. Will people be scored relatively among their test group (people who take it within the first few days), or will they be scored against an absolute standard regardless of the cohort's performance?

Also, with regards to the bell curve for the quant and verbal section -- is it based on deeper historic performance records (ie, we will be benchmarked against everyone taking the GMAT this year), or is it just benchmarked against the folks who take it around the same time as you? I'm probably really overanalyzing here, but honestly, I secretly kind of worry that all the GMAT prep providers will all send their teachers to see this new section in the wild on opening weekend, and so the competition might be much stronger. Or perhaps weaker, as all the strategic test-takers would avoid this window. I don't really know.

Perhaps these are weird externalities to consider, but I'd love to hear any perspectives on this before I commit to a new test date.