Please read the below blue post explaining what the current testing is focusing on. They're not shoehorning anything in -- they've gotten almost everything they need from testing already -- 25man tests are just numbers and recently changed mechanics. Be thankful they're doing any 25-man testing at all.
That said, they've made it clear that the patch, while targeted for the 27th, could always be delayed.At this point, we're just sanity-checking the numbers to make sure that the 25-player scaling is appropriate, since we've tested these encounters a couple of times already, and often on Flexible mode as well. We may spend longer on some fights that have seen more meaningful mechanics changes since the 10-player version, but in general we keep the fights up long enough to see what we need to see, and then shut them down.