There has been a lot of talk (I suspect from Penny's friends, family,supporters and office) about how Malaysians who are dual citizens "automatically" lose their Malaysian citizenship.
This is not true,and the relevant provisions in the Malaysian Constitution make it clear that revocation of citizenship is at the discretion of the Malaysian Government.The reason is simple: The Malaysian Government does not want to lose its rights and jurisdiction over citizens, who may claim the protection of a foreign power.
Stripping dual citizens of their Malaysian citizenship is therefore punishment for breaching the laws of the land,and done in a manner that the wrong doer is often left stateless, and/or loses rights to ,among other tings, property in Malaysia. In any event, it is a penalty for a wrong,and hence the process of formal renunciation which allows a legal ,happy parting of ways.
Senator Wong may therefore have committed an offence in Malaysia. That too is factor that may disqualify her from being a senator.
ReferencesDual citizenship and other no nos that will give you the boot