You've literally missed the point of it. its not a 180 at all, since they aren't even reverting him back to his pre 5.22 state.
they buffed his W range to compensate for slowing his WQ poke considerably
What they did: (no animation cancel - you must now wait until his W finishes to cast Q) which means that instead of his WQ poke taking 0.25s to execute, it now takes 0.4s to execute (time it takes for W to travel)
that is actually massive, and nothing compared to the leblanc W nerf
so to compensate, they increased the range of his W from 600 to 700... but with the same missle speed, it takes even longer to execute a WQ - 0.47s to be precise, which is a 17% speed nerf.... which is no compensation at all.
so they increase the missle speed so that his WQ still takes 0.4s to complete.
the end.