I doubt the WSJ would inflate Cruz’s numbers to account for their deflating Trump’s. Although I do note Kasich got a relatively big bump. IMHO this poll is just an outlier, and the only numbers it has right are Rubio’s, which are consistent with other polls. Oh, yeah, and Yeb! or Heb! or however you say his name.
I loathe the WSJ, so I always see red when they do something. So far it’s the only poll out there like this, so perhaps it is an outlier. If some other polls pop up like this one then we will have an interesting race.