Relevance of PPT export filter

[Ilmari Lauhakangas]

In https://bugs.documentfoundation.org/show_bug.cgi?id=89853#c18 Regina 
has a good point:

"do we really want to work on _export_ filters for an old binary file 
format? We have already dropped export to the binary StarDivision 
formats (.sdd) and to the XML-formats of OpenOffice.org1.0 (.sxi)."

In concrete terms, should we declare bug bankruptcy on PPT export issues 
and move any new reports to WONTFIX from now on?

Ilmari