I am seeing some webmasters and SEOs pick up on a new useragent potentially from Google named google-Read-Aloud. The useragent references a URL to Google's useragent page but this specific one is not listed on that page.
It reminds me of the google-speakr useragent which Google told us after was related to Google Go fetches a page to make sure it has the most up-to-date information before it translates it to read aloud.
But this one may be the same or different, we are not sure. It sounds similar.
Gaston Riera posted about this on Twitter and share a screen shot of the log file:
Have you seen this useragent?
I'll try to find out more on this.
Update: Google just renamed the google-speakr usergent to this, Danny Sullivan confirmed on Twitter:
Remember the whole google-speakr useragent? That's what we renamed that to.
— Danny Sullivan (@dannysullivan) April 5, 2019
Forum discussion at Twitter.