I'm the only user on this machine and I don't remember adding the Keep extension. Just seems a little suspicious that G launch a competitor to Evernote and suddenly it's replacing it. Points against this theory, Both Evernote and Adblock required reloading after the Chrome update and I had clicked on the Keep sidebar in GMail to see what it was.
Not sure what happened here but - Went to clip a page and the Webclipper extension icon, which is normally in the first position next to the omnibox, was no longer there. In it's place was a "Save to Keep" icon. I don't remember putting Keep in that location. When I went to the extensions page it had a Reload button next to it and the Webclipper returned. Running Chrome 70.0.3538.77, recently updated, on Windows 10