Will the EntitySet that listens to “ComponentA”, maintain the order in which these entities are added/changed when I make a call to entitySet.getAddedEntities() or entitySet.getChangedEntities()?
Looks like it won’t maintain the order. Looking at the source code I noticed it internally uses a HashSet for keeping addedEntities and changedEntities.
Probably if you need this then there may be design shift in your code that may achieve what you really want.
Edit: think about it this way, any of those entity’s components might have changed 100 times between calls to applyChanges(). “Which entity had componentA changed first?” is a difficult question to answer.
…but moreover, it should be an unnecessary question. I suspect there may be a missing system or component but I cannot tell without knowing why you needed it.