Here is a simple calculation. 5/2,500,000 *100 = 0.0002% Put another way 99.9998% of Samsung Note 7 replacement are perfectly fine. A total of about 40 counting both the replacement and the original. If we double the 2.5 million to get the amount of total Note 7's that 40 still means less than one hundredth of one percent
Less than one one hundreth of one percent of Note 7 phones have had a problem with catching fire while charging. A problem which is NOT NEW, and NOT UNIQUE to the Note 7. As the gentleman in the following video explains so well if you plug an expensive phone into a el cheapo charger you are going to get bad results.
Basically all cell phone batteries are highly stable explosives which are only kept in check by circuits that regulate how quickly energy is let in and let out. In short resistors in the circuit keep too much current from flowing into the phone. There has to be one such resistor in the charging cable itself. I am no expert on cell phones, but they need to have variable resistors in them to allow for different charging cables.
In a related video someone tears down the battery on the phone and notes the fire does not have to start at the charging port for the charging circuit to be the issue. If the charging circuit is not set up right. If it is not robust enough to account for the use of the cheap dollar store chargers your phone will explode.
I don't think I should have to return my phone because some fools I mean folks decided to charge their phone on a bad circuit. I should not have to return my phone because they used a cheap charger. We should not have to go through this drama because a few were unlucy enough to have a power surge at the time they were charging their phone on a ungrounded ciruit without surge protection.
You should do what the CPSC and Samsung say and return the phone. Not because there is an actual realistic chance you will be one of the people who's phone will catch fire. Odds are if you choose to keep and use your more than likely 100% great and groundbreaking phone and you have a problem, ANY normal problem it will not be covered by Warranty, insurance or anything like that. If your note seven gets a bad screen after a while and will not respond to touch, or just stops working, you will be SOL.