The J5 was released back in April, if it was having the same issue as the Note 7 (August), I'm pretty sure there would have been a lot more news on this.
Yeah, this really isn't big news. The Note 7 was notable because it had 30 within 2 weeks of release, this is more of a random event and bad luck to the owner. While I would never buy this phone myself (it sounds like a cheap crap Android Samsung cranks out),,I wouldn't worry about more blowing up. Hell, even if a different model Samsung blew up tomorrow, I wouldn't deem Samsung dangerous. Samsung's shipped so many phones now so it's inevitable.
The J5 may be cheap, but it saves money and offers features in the right places, definitely is not crap. The battery is removable, there's a microSD slot to extend the low built-in memory. The CPU is quite fast, and the screen is absolutely sufficient for me, even if its resolution is much lower than on high-end models. I got mine (a dual-sim model at that) as a bargain for 150EUR (no contract), where a top-of-the-line model would have cost at least 3x that. The only thing I'm missing so far is better sensors (i.e. better precision of the GPS when I go jogging, or acceleration sensors for use with e.g. planetarium apps). I certainly don't feel much of a difference compared to my wife's previous S5Active or my previous Nexus5.
In the news articles, I didn't see whether the battery used here was the original provided with the device. Given the model's quite recent, I don't suppose the battery to have been replaced yet though.
A propos exploding batteries, anyone left here who remembers Sony's laptop batteries exploding on-flight? The problem isn't exactly new...