If you are going to perform a statistical test, i'd isolate a specific hypothesis to test. For example, the original post mentioned a theory that high quality rare items like chaos would drop more frequently with IIR than IIQ, so i'd partition the dataset into these rare currency items to test that hypothesis. Or test a hypothesis that lower value poe currency purchase drop more frequently with IIQ vs IIR.
It's worth mentioning that the P-value of any test like that can't be trusted, because we've developed that hypothesis from looking at the experimental data. This is actually a big problem in experimental science: if you do the experiment first and notice a trend, in order to get a sensible experimental result you need to do another test of that hypothesis. Many people don't, and pretend that was their hypothesis all along, and then it looks like the experiment confirms the result with far too much confidence.
What you've done, assuming your math was correct, is simply establish that overall poe buy currency drops for IIQ and IIR groups were statistically significantly different, which is what everyone would already expect before the video was posted. Without doing a 1 tailed test with the specific direction in mind (IIQ < IIR) you've failed to confirm/deny Slipper's claim.
While they publicly say that they can and do change droprates this is probably very rare. This is done so that if there is ever a case where a drop rate has to be adjusted and it is somehow proven by the community then GGG cannot be held accountable as it is in their right to so.