Beethoven removed the dedication after Napoleon
accepted the rank of Emperor, not because of his
behaviour to the Prussians.

Well, if we want to get into this, the symphony was never "dedicated" to
Napoleon but was originally _entitled_ Bonaparte. Apparently the only source
for the story of Beethoven changing the title of the symphony because he was
angry that Napoleon had proclaimed himself emperor was a student of Beethoven's
named Ries. He claimed to have seen Beethoven, when he got the news, tear up
the title page of the score, fling it to the ground and stamp on it.
Unfortunately, the original score of the piece no longer exists, so there is no
way to verify the story. A copy (date unknown) with corrections by Beethoven
still bears on the title page "intitolata Bonaparte," but they have been
crossed out, presumably by Beethoven. Napoleon's coronation took place in May,
1804. In August, 1804, Beethoven offered the symphony to his Leipzig publisher
with the note, "The symphony is actually entitled Bonaparte..."
When the piece received its first public performance in April, 1805, it was as
the Eroica, not the Bonaparte. Joseph Schmidt-Gorg, who knows as much about
Beethoven as anyone--if not more--believed that as B. evolved his ideas about
this symphony he decided to make the work commemorate the idea of the great man
in general, rather than have it refer to one specific individual.
About the controvery over the original title, he writes, "In the case of the
Eroica, so many incorrect and misleading statements have been handed down that
it provides a perfect example of how difficult it often is to ascertain which
among contradictory accounts is the correct one."
Source for the above: "Ludwig van Beethoven" by Joseph Schmidt-Gorg & Hans
Schmidt, Beethoven-Archiv, Bonn.

As an aside, I found it astounding that anyone, particularly someone who tends
to put forward the German side of things, could possibly confuse the Eroica
with the Choral. Could it be that Mr. E's musical taste runs more to Bon Jovi
than Beethoven?