Cyanogenmod (and every other custom ROM) is, and always was, an extreme minority of Android users. I don't really see how this changes anything.
There are several other minor features also which made the cut from AOKP roms to AOSP.
And once you spend enough time on websites like [Google-My Activity][1] .You would realise why many would want to avoid the google ecosystem owing to their privacy concerns. Most of the alternative android app markets like F-Droid survived majorly because of custom ROMS. While their numbers were not huge, they were the few who preferred keeping control of their devices and the information that they shared. Almost 80% of the custom ROMs are forked off CM. With CM being dead,this would affect others too.
You can also thank CM for ensuring that devices have a much longer lifespan than what the OEMs deem.
Also, IMHO, it's a bit of a stretch to say that the Google Now shortcut was inspired by PA's Pie controls. One is just a shortcut to an enhanced search feature, and the other is... not unlike iOS's Assistive Touch feature on steroids. The only commonality is that they occur near/around the home button.
EDIT: And in fact, my Galaxy Note II had a "long-press menu button to trigger search" since the dedicated search button was removed -- nothing particularly unique about that paradigm.
While Cyanogen Inc. may well have been Google's biggest "threat" when it came to control of Android, it wasn't even that big a threat to begin with. They were always beholden to Google's source dumps, as was any other ROM distribution. I'd argue little has changed in terms of how much control Google has over Android's destiny, and Cyanogen Inc.'s (impending) death doesn't really move the compass in any meaningful way.
ApOps was removed by google[1] .
I agree with the little has changed bit. But I think we should give them credit for innovating quite a bit on the platform.And with Google's version of the OS, there were little outside options.which will reduce more drastically atleast till all Custom ROMs start forking of LineageOS.
[1]: Minor quibble, but CyanogenMod's Privacy Guard was a glorified UI on top of App Ops that Google had already been developing.
I agree that CyanogenMod did bring innovations to the table -- I'm in no way trying to diminish that. Just clarifying attribution where due.
Speaking more generally, there is no doubt that custom ROMs answered needs/demands that Google just couldn't satisfy in the same timelines. Custom ROMs deserve tons of credit for prototyping and "market testing" concepts/features for Google. The good news is that -- by and large -- most of the low-hanging fruits have already been incorporated back into mainline Android. Nowadays, I've personally found fewer and fewer reasons to use custom ROMs (outside of the ever-important need to extend device lifetime anyway -- probably the biggest thing remaining that Google likely won't ever attempt to satisfy).
[1] http://www.androidpolice.com/2013/12/11/googler-app-ops-was-...
[2] https://www.xda-developers.com/protecting-your-privacy-app-o...
If there are no alternative OSes, the fact that most of Android doesn't really matter any more.