Again I think comparisons to Mary are appropriate. Dean didn't open up to Mary the minute she came back to life, (a) because that's just not who he is, and (b) because Drama. It took him until 12x22 & there are still things they have to work on. The s13 Dean/Cas plot is being structured like the s12 Dean-Mary plot (compare Dean's last scenes in s11 and s12). It's *important* so it's not getting resolved YET. TPTB wouldn't have killed Cas if nothing was going to change.
