A victory at Rio Salado will give them a lot of breathing room to establish themselves firmly in southern hispania.
The marinids are, however, based in north africa, and are forced to prioritise their interests there. As such are going to be at a disadvantage vis-a-vis the portugal, castile, aragon after these all recover.
They aren't too popular with the nasrids, but are found preferable to christian domination.
Nearby France is too busy with its own affairs to care either way. It may even prefer iberia to be more disunited
Assuming the Marinids consolidate their new territory well, and avoid getting too distracted in africa, and overcome all three iberian christian powers (who will almost certainly form a coalition) plus european volunteers, then they will have until the end of France's hundred years' war to remake Al-Andalus.
After that, they are going to be threatened with absolutely massive revanchist crusades. I'm not sure if coordinating with the Ottoman empire would work all that well, as the nearest major power is France, which was wholly uninvolved in the Habsburg-Ottoman wars (for obvious reasons) and which will absolutely be involved in Spain.
France will have an excellent opportunity to expand into "heathen Spain" and grab a decent chunk of it, under the guise of liberating the christians there, who will almost certainly help them.
The Marinids will eventually fracture or be distracted by N. African events, and the French and/or their Spanish puppet states will expand into Al-Andalus again.
That said, maybe the Marinids form common cause with England and together cripple France before the HYW ends. That requires a lot of foresight, though, as well as some luck