This story was run to distract from Obama being referred to DOJ for evaluation of criminal charges by the DNI.
The WSJ was used because it hasn't blown all of its' credibility like other MSM sources - but it has participated in the past at times, and it does have a large staff with many MSM ties.
It was very atypical of the WSJ to run this story since 1) it offers up a damaging claim without any way to prove the validity of it, 2) it did not contact both sides of the story to get opposing views - the Trump team was never contacted and their side not presented (the Trump Team did find out about the WSJ intent to run this at the last minute and were warned that it was not true, but they ran it anyways without verifying.
Now, history tells us what will happen next. There will be a years long legal process at the end of which the WSJ will retract the story and pay Trump a lot of money for libel.