I see it as an attempt to involve themselves with the platform implementors or become acquired by them. Apple, Google and Microsoft will all implement their own version of this in the next few months and f.lux will become irrelevant. Whether or not one of them partners with f.lux or not is what they hope for, I believe.
There is room for third party alternatives to system features.
e.g. spotlight search / watson, iCloud Drive / Dropbox, 1password / iCloud keychain, Instapaper / Pocket / Reading List
Apple's going to go for lowest common denominator, while third parties can go for a smaller slice of that market.
I would love to see both a system feature and enabling 3rd parties to offer this functionality. Don't expect to see it on iOS... it's too small an app class to expect a custom extension point for it.
