It seemed like the automatic layout was applied when I removed layoutConditions: go.Part.LayoutStandard & ~go.Part.LayoutNodeSized.
Even with the use of layoutConditions: go.Part.LayoutStandard & ~go.Part.LayoutNodeSized, is it possible to enable automatic layout for nodes?
That flag on layoutConditions,
go.Part.LayoutNodeSized, explicitly controls whether a node changing size causes the layout to be invalidated, thus resulting in the layout being performed again before the end of the transaction.
So if the size of a node depends on the text in it, and if the text is changed, then it stands to reason that the node changes size. Whether or not that invalidates the layout depends on that node’s layoutConditions flag and Layout.isOngoing.
Read more at: GoJS Layouts -- Northwoods Software