What was the cost of the replacement? I had a similar problem with my 9350 around the same time as you did. I'd bought it 3 years earlier. My laptop was out of warranty, and Dell's best offer was for me to ship the laptop to them, and they would replace the battery for a cost of around $500 CAD. They refused to ship me the battery on its own, saying it was not a user-replaceable part. Since this is almost half the price of a new laptop, I declined and took my chances with a Chinese aftermarket battery for around $60 CAD. It's working reasonably well so far after 6 months.

I personally don't get any laptop that doesn't offer in-home service. And in my experience, Dell has the best in-home service out of all that I have tried.

The only problem with Dell is they can't get their cooling done properly! Most of their laptops are portable furnaces (which is a shame and one of the biggest reasons I have avoided Dell despite some tempting options). And exposure to heat is one of the things that damages batteries in the first place. This is why you should take the battery out(if that is an option) if you use your laptop as a desktop or use a cooling pad to keep the battery temperatures managed.

Overall, the biggest risk of swollen batteries is when they are in tight enclosures with no room to expand. So manufacturers locking things down are actually making more fire risks.