Majapahit not collapsing wouldn't prevent the northern coast of Java to convert to Islam, as the Islamization process starts before the collapse. It would probably delay the Islamization of the interior through, and the spread of Islam to other islands. Plus most of the masses aren't Hindu to beginwith, they follow a weird mixture of Hindu-Buddho-animism, which in OTL simply add -Islam on the gado gado of the syncretism that Dutch ethnographer simply calls Abangan Muslims
The best way to avoid Majapahit collapse would be preventing Paregreg War. The emergence of the Eastern Court has began since before Hayam Wuruk dies (1376 at the very least), which relations begin to grew worse in subsequent times and set the stage for Majapahit's slow death. So the PoD IMO should be earlier than 1376.
Even if Majapahit did survive, everything outside of Java-Madura-Bali isn't particularly important to Trowulan. Majapahit was running on Mandala system, which translate to bullying city states outside of Java to give tribute to the metropole and leave them alone. A certain Adityawarman even claimed the title of great king of kings (Maharajadiraja) and Majapahit still counted him as their tributary.
I don't know how Tondo is important to Majapahit. Most of their wealth came from controlling Molucca tributaries and other Eastern Islands while also controlling Strait of Malacca. As far as I knew, the fall of Majapahit isn't connected to Tondo.
For treaty ports, the most famous one in Java, Sunda Kalapa, was given to Portuguese as a gift by the King of Sunda as part of "fuck Muslims" pact between Portuguese and Hindu throne of Sunda, which was threatened by Majapahit mk2 that we usually calls Demak Sultanate. If Majapahit doesn't face similar threat, Java wouldn't be so inclined to gave any. The vassal kings of outer islands, on the other hands, might be more willing