It is absolutely possible to hear the same sentence from bilingual French speakers with a complementizer originating from French que.
Nou konnen ke ou nan konplo.
In Peleman’s (1978) dictionary, the entry ké reads: "It is not a loanword from French like so many others, but it rather results from a lack of respect for the creole, where ke is not needed in cultivated speech as well as in popular speech. It is a bastard which, thanks to the school and to publications in creole, although there are very few of them, sees its chances of survival INCREASE from day to day. The language doesn’t need it at all.” (our translation)
Source: Dejean 1982: 54
Source: Desmarattes 1983: 12