The link you’ve shared here talks about the Führer Oath being created in August 1934 but not becoming law until mid-1935, which seems to roughly agree with the date in the post you’re disputing. I can’t find much to support the claim about a surprise assembly, though, at least from a cursory search.
I keep seeing this historical “fact” but I can’t find anything corroborating it. “Hitler oaths” were already being taken since 1933, by June of 1935 the Reichswehr was replaced by the Wehrmacht.
The link you’ve shared here talks about the Führer Oath being created in August 1934 but not becoming law until mid-1935, which seems to roughly agree with the date in the post you’re disputing. I can’t find much to support the claim about a surprise assembly, though, at least from a cursory search.
It looks as though his post is taken almost verbatim from this substack post: https://thecycle.substack.com/p/from-hitler-to-hegseth
which doesn’t inspire the most confidence.