Most likely WvW focused expansion will never happen.
We can still hope for new WvW content tho that is also on a low chance to happen specially new map (remember how badly Desert Borderland was received by players, tho i personally love it)
WvW needs major balance patch to fix its current problems. Like Boonballs we got now in wvw. A good guild group won't ever be wiped in a fight unless they fight vs other good guild group.
Skills like projectile reflect/destroy/block need to be removed completely from wvw or their cooldowns to be doubled/tripled because with those skills make a boonball even more unkillable.