I doubt that. The particular topic had several replies and it seems not possible for normal users to delete their own OP in such cases:
You don’t have permission to delete this topic. If you really want it to be deleted, submit a flag for moderator attention together with reasoning.
The first one was in German. A user complained that Picard had deleted their files(?).
(They were throwing a tantrum, swearing in the topic title etc. and, as you implied, it might’ve appeared hostile.)
I assume the files were just moved to an unexpected directory.
Later when I went to check on the topic once again I was no longer able to view it.
@outsidecontext might also remember that topic.
In the topic about cover art @yindesu mentioned OP was demanding something along the lines that editors should upload full scans when adding releases.
Quite a lot of people replied in defense of the MB community. E.g. that not everyone has the time and/or equipment to provide scans, some are hesitant to upload booklet pages consisting of copyrighted text only, etc.
If I remember correctly the original post was flagged at some time and since I know Discourse has self-moderation features I suspect it was automatically deleted.
People get worried when things are automatically deleted while no one seems to be looking.