Not sure what metrics YC collects on each of its cohorts, but if "Cycle Length" and "Total Cycles" are two of them (i.e. end-to-end time through build-measure-learn loop), then it would be valuable to see if January's teams deviate, in a meaningful way, from the established average and mean.
Hypothetically, you'd think that "Cycle Length" would decrease as less cash in hand forces teams without product-market fit to tap into higher gear (or sustain that same high level of output), rather than spend valuable attention wondering about how to get a piece of the "carcass" should things crash and burn. Total cycles would then move up and to the right, as teams get a few more in near the end of their runway.
That said, there are at least two additional potentialities.
1. "Cycle Length" and "Total Cycles" are already running along their respective natural asymptotes.
Consequence(s): A. Awesomely cool discovery re: limits of productivity! B. The number of founders able to remain highly productive while simultaneously squabbling (and providing PG w/ massive headaches) decreases.
2. The "Starting Date" for raising an additional round of financing shifts to the left (i.e. becomes earlier). With less cash in the bank, and hence a shorter runway, the average starting date for teams w/o product-market fit to begin seriously committing time to fundraising shifts "earlier".
Consequence(s): A. If more time fundraising = less time building, then the average total output of a team, in the 12 months post-YC, could decrease.
Mitigation: Personal access to the best VCs in the world could mean that the length of a "Funding Cycle" (i.e. total time spent raising a round) decreases, thus offsetting consequence 2a.
It'd be great if these numbers were something YC actually collected. If there's a science to building companies, you could certainly glean great insight from those digits.