It would be a big thing if they intend to become the mecca of world football, it is not impossible, but it takes a very long time, and keep in mind they will compete with Europe which can now be said to be the mecca of world football.
But the steps they are taking now have at least made them better known to many people. It doesn't have to be the mecca of world football, but they have to be able to show that the competition here is no less than the world's top leagues, such as the English League. They have shown that now and hope they can maintain it.
They do have the ambition to become the "mecca" of world football but it is not easy at all. They may have the money to attract the world attention but is money the only thing needed to make Saudi Arabia, the central of Global Football ? I do not think so.
In order to achieve this goal, it will require a significant time and investments. It will not be easy for any country (especially any Asian country) to come up and challenge Europe's dominance in the sport. Yes they have the intent, they are attracting not only high profile players but also coaches and investments into their domestic league. Saudi Professional League's growing reputation is a right step as how they are positioning themselves as a competitive football force.
I agree with you, they do have money, but money is not the only factor that can immediately make them the best league or the mecca of world football. Not to underestimate, they also come from Asia, which we know Asia has only recently been able to show tight competition in the international arena such as the World Cup. The ambition or motivation to do that is legitimate, but we can also measure for ourselves how far it can be done, and if it can happen then how long it will take them. In the World Cup alone, countries from Asia have never represented to become champions.