The only guidance I have read recently tells me that "Resume own navigation..." means that "ATC expect the crew to regain the flight planned/cleared route as soon as possible, NOT BYPASSING ANY INTERMEDIATE FIXES" (my bold).
Furthermore, I'm instructed that "Resume own navigation direct to ..." means that "ATC expect the crew... to fly direct to that fix". The exception being Latin America where the term "direct" means "proceed along the flight planned route without delay".
I don't fly to Latin America, so I can't comment on the last part and I disagree with the given interpretation of "resume own navigation" and I've never seen anyone apply it in that way.
G W-H