You would still have 100,000 miles and qualify for Executive Platinum, but you would only have 90,000 points since you were rewarded for business class travel but penalized for cheaper economy class travel. (travelcodex.com)
Even cheap economy fares are eligible for 5,000 miles per roundtrip. (rewardexpert.com)
For most leisure travelers, this significantly reduces the number of miles earned since travel hackers tend to pay for cheap economy tickets and redeem miles for expensive premium cabin tickets. (rewardexpert.com)