If one does not use the general option, the title, date, acronym etc. are suppressed. This information is contained in the DFG template: http://www.dfg.de/formulare/53_01_elan/53_01_de_elan.rtf.
This was not the case with the version of dfgproposal.cls that was delivered with TeXLive 2018. Since then, \ifgeneral has been moved up, see PR.