Arabia is no doubt still the most played map in ranked games, but the number is a bit misleading. You can see there are maps which dont belong to the current map pool, despite "Over X DE matches on patch 40220 analyzed!" being stated on front page. Other non-fixed maps should get their play rates doubled (or tripled?).
Also Arabia only has 44% play rate at <1000 elo , which is probably the majority in the official forum. Imagine some low elo arabia players are like "Meh it will be included anyway, let me vote for other maps", along with some genuine Arabia haters, Arabia being left out isnt completely impossible.