In his katha of Japji Sahib Gyani Thakur Singh says that if a good muslim, adhering to all aspects of islam reach paradise. however they after a period of time they are returned to the world.
Gyani Ji emphasises the need to meditate on naam, im assuming that Muslims dont do this. He says that a person who does good deeds, but who does not meditate on naam, upon entering sachkand are given a garland. each flower on the garland represents a good deed. slowly these flowers die and perish, and when all the good deeds have been exhausted through time in this way the person returns to the world.
But as Sikhs maharaj tells us to jap naam. in the mool mantar for example. so i guess its different for gursikhs.