No strong rumours to suggest another aircraft but I would be shocked if another one was not added. The only problem is Ryanair have to agree routes with the authorities in advance, and now Air Malta are in trouble it's a question of does the government protect Air Malta or have in place an airline that can continue to deliver tourism growth to the island....which is in no doubt Ryanair.
I would expect at least 1 more to be added, maybe just for 6 months April-October in the same way ALC and AGP are increased in size for the summer for holiday routes.