When Disney took over Lucasfilm, and announced the creation of new movies, current Extended Universe works were deemed to be non-canon.
Interestingly though, there seem to be a number of plot points within The Force Awakens that seem very similar to events that took place in the EU (renamed "Legends" by Disney).
The son of Han Solo and Leia Organa trains as a Jedi with Luke but turns to the dark side. (Jacen Solo in EU).
The name 'Ben' is used for a descendent of Anakin Skywalker (in EU this was actually Luke's son, not Han/Leia's).
Luke's Lightsaber that he inherited from Anakin turns up again despite seemingly being lost at Bespin (in EU Luke encounters a clone of himself, cloned the hand he lost fighting Vader and wielding his lightsaber. Luke later gifts this to Mara Jade).
A stormtrooper becomes disillusioned and runs away after being ordered to kill civilians (In the EU novel Allegiance four stormtroopers run away and become vigilantes for the same reason).
There are quite possibly other examples.
Additionally there is evidence that George Lucas was fully aware of at least one of these plot points.
George Lucas actually got directly involved the Jacen Solo storyline: 'it had been the creative team's intent to kill Jacen Solo in Anakin's place and have Anakin become the major hero. This was abandoned when Star Wars creator George Lucas vetoed the idea of Anakin Solo becoming the dominant figure, and the brothers' dramatic roles were swapped. Jacen Solo became the central figure of the arc; according to editor Sue Rostoni, "in many ways, the NJO is really his series."' - http://starwars.wikia.com/wiki/Darth_Caedus
Is there any evidence that the writers were paying homage to the EU here? They certainly were happy to pay homage a LOT to A New Hope! Or is this all just coincedental. The EU is so massive that pretty much anything that could reasonably happen has happened. However, some of the plot points are pretty well known, so can we reasonably assume that somebody being paid a lot of money to work in the Star Wars universe may have been aware of these things.