Many bugs have been reported against classdef which all relate to the fact that Octave does not implement an array container for objects.  Hence, placing multiple objects into an array with square bracket notation fails.  As does trying to concatenate objects into an array with square brackets.  As does transposing arrays of objects.  And Octave is obviously not Matlab compatibile here as certain metalist functions return object arrays.

The currently suggested workaround is to use cell arrays which are a container that supports concatenation, transposition, etc.  But there are still differences.  See bug #53906.  For example, the properties of an object can be referenced using dot notation from an object array just as they can from struct arrays (which possibly provides a clue on how best to implement this).

Filing this bug report to be a central location for work on this topic.  I will point other bugs to depend on this item.