Can you please point out where in my source it states that it was the type of election you say it is because to me it seems to say they made public votes about the unification. Maybe there is something lost in translation as I am reading the german version and you might not be or something else.
This is also the part I need a source for: That the elections were made out to be a vote about the unification process.
The Article you stated from the GG just states what we already agreed on: That there was a vote to be held and if the vote turns out not in favor it will not happen.
From what I have read up now the unification was not done under article 29 but with a seperate contract that the elected parties from the DDR and the BRD signed to unite the parts of germany. I am not sure if this was against the article 29 but I can't find any information if it was or wasn't.
The contract didn't include anything about voting about it.