The TL:DR here is that ethereum is (in my opinion, thankfully) going to have a damn hard time hard forking because so many other crypto projects are interconnected with it.
A fork at this point would mean each of those dependent projects, (especially defi apps) would also need to fork into two supporting versions to work with both chains. This just isn't likely to happen.
In other words, Ethereum is ethereum now, and the prevailing popular client will always win out.
Also the title of the article is clickbait BS, the defi apps will always work with one chain, even in the event of a fork.