For this parameter ...
allowNoIndex boolean
Allows the data view saved object to exist before the data is available.
For this Kibana API ...
Create a data view
POST /api/data_views/data_view
Which is documented here ...
https://www.elastic.co/docs/api/doc/kibana/operation/operation-createdataviewdefaultw
Should the documentation indicate what the default value is, since this is a boolean parameter?