Does changing one’s name change the divine decree?

Changing one’s name does not change the divine decree, but it may have an effect on the person and his life. 

Al-Bukhaari (6190) narrated from Ibn al-Musayyab that his father came to the Prophet (peace and blessings of Allaah be upon him) and he said, “What is your name?” He said, “Hazn (meaning rough).” He said, “You are Sahl (meaning easy).” He said, “I will not change the name that my father gave to me.” Ibn al-Musayyab said, “And we have had roughness (in character) ever since.” 

With regard to the phrase “And we have had roughness (in character) ever since” – 

Al-Haafiz said in al-Fath:

Al-Dawoodi said: it means that they were harsh, except that in the case of Sa’eed this harshness showed itself only in anger for the sake of Allaah. Someone else said: it refers to the toughness that remained in their character. The genealogists said that his son had some bad characteristics that were well known among them, which you could find in all of them. 

Ibn al-Qayyim said: 

Because names have meanings, it is wise that there should be a proper connection between the meaning of the names and the object that is carrying the name. It should not be the case that the meaning is not suited to the object and there is no connection between the meaning and the object, because this is what is decreed by the Most Wise, and reality testifies to that. Indeed names have a great impact on the objects to which they are applied, and the objects that carry these names will definitely be influenced by these names, whether these names are good or ugly, whether they refer to meanings of lightness or heaviness, kindness or cruelty.” 

Zaad al-Ma’aad, 2/336 

And Allaah knows best.