They never mentioned these nationalist butchered entire malay monarchs, those malays who served dutch administration such as police etc were butchered and malays forced into hiding before independence. No more " kerajaan" left in Sumatra. Malays had to use other non malay names to escape. This happened in 1946.
If this had not occured, Sumatra could be a independent malay nation unlike currently where it is under javanese rule.
Thst is why javanese does not recognise bahasa melayu as national language but rebranded it as bahasa indonesia. Malay Nationalism is a very sensitive issue for them as it v9nstitutes three of the largest islands. Sumatra, Kalimantan and sulawesi.
And islands between peninsula malaysia and Kalimantan in south china sea are all populated by malays, speak malay and watches p ramlee movies.