„Freude über etwas“ or „Freude auf etwas“

Question

It is said that sich freuen über etwas applies to something that has come to existence while sich freuen auf etwas applies to something that is yet to become ;

I am wondering whether this division of labour is carried on into the usage of the noun Freude :
does Freude über etwas applies to sth. that has existed while Freude auf etwas applies to sth. that hasn't yet come to existence?

I read the following sentence from a book (CONTRAST by Elisabeth Rudolph) :
,,Er vermutete ein Anliegen und empfand eine gewisse ängstliche Freude darüber ;
doch sprach sie vorläufig nur schöne Worte.''
To me, the phrase Freude darüber should be better substituted with Freude darauf, because he took delight over rather his supposition, which has not yet come true, than an Actual situation. Would any one agree or disagree to this point?

Answer 1

I would disagree.

He thinks theres an "Anliegen", and he's glad because of that. (Er freut sich ÜBER das Anliegen (which he thinks there would be))

The other possibility would be, he KNOWS theres an "Anliegen", and he can't await to hear it. (Er freut sich AUF das Anliegen)