This goes out for all kinds of routers and not just the MAKITA one. If your router has the right blades and bits, then yes, you can work on aluminum steel as well. Now regarding this specific model of the MAKITA brand, you have to keep in mind that this product is a relatively compact and light router.
So even though you can work on aluminum with this, make sure it has the right pressure or else expect some inaccuracy or perhaps even damage to the router itself.