Selected answers from the Dumb SEO Questions G+ community.
Shubham Patodi: No.. Google never intimate you if your site is violating the guidelines of any update. But at some how it gives you some indications about suspicious activities or links of your site in the section of Manual action. So basically Google doesn't give you any direct indication about any suspicious action. ;
Top Ranks: Google won't send any msgs but you can find out in webmaster tools, if you traffic went down near to that update date then your site has been effected.
Anuj Singh: Thnaks Shubham and top ranks for nice comments...
W.E. Jonk: From the expert panel in this weeks SEO Questions hangout on air on 00:45:45 into the YouTube video: