2013 shift is overblown, 2013-2014 school year shift

>-Hashtags and emoji become popular

Hashtags became popular. I don't really think emojis blew up here it was more of a gradual thing from what I recall maybe im wrong though.

>-Flat design becomes popular. Skeuomorphism dies off.

IOS7 going flat doesn't neccessarily mean all interfaces went flat overnight. Again 2014 is what makes all these things become fully normalised, sept 2013 was just the start.

>-Instagram blows up in popularity

It was also popular late 2012

>-Facebook begins to decline in popularity

I'd say it was about neck and neck with instagram at the time.

>-PS4 and Xbox One come out


Already mentioned this in the description, like I said huge reach no one had them and no games were out for them.

>-Netflix releases original series like Orange is the New Black and House of Cards. It begins to replace cable and physical media from this point forward.

Streaming didn't start overtaking cable until late 2015/2016

>-Spotify starts taking off, replacing iTunes

I noticed people using spotify in 2012.

>-Electropop is no longer the dominant music genre.

It wasn't even the dominant music genre in late 2012.  

this, it felt miles apart

I just don't see it and I wish I could. There was somewhat of a difference beginning to end of the year but it's more like your average garden variety pop culture shift. 2010, 2011 and 2015 were arguably bigger shifts that decade.