I see two pretty distinct issues here: 1) most people's favourite app is going to die, and 2) many subreddits will be negatively affected by this move: prime example is /r/AskHistorians.
Personally, 1) is not really an issue and people are enjoying the outrage train, and that's ok and valid and whatever, but it's a third party app. It's a no-brainer decision to try to kill it if it's hindering your ability to make more money. At the mid term is a great incentive for Reddit to improve their shitty app experience ("but Ads!" yeah, ads of course, you're not paying shot for using it, it's an impopular but pragmatic business model)
But 2) it's the one that's really concerning. Hopefully they reverse this course for this point specifically cause this has a measurable impact on eyeballs, which ultimately means money.
inb4: "Apollo dying means less eyeballs too dummy", yeah as I mentioned before the outrage is the fad. Once it passes, will see how much people actually leaves (little to none alternatives for Reddit btw). My bet is that could result in a small hump, if anything, in the long run.