See the other comment thread I started as it's directly what I wanted to know too! tl;dr ~5% higher drop rate on average.
It's not 5% higher drop rate on average, OP didn't give enough context even if the math is entirely correct. It's a 5% increase on the average drop rate only if everyone who does the content doesn't stop until they get said unique (which isn't and will never be the case).
The real number would likely be around +2% or less. Not only that, but that direct increase only applies to chase uniques, which people actually go for. You have to compute all the other uniques which will no longer drop because many people now finish their grinds earlier.
Overall, I'd be really surprised if it meant more than a +1% increase.