Yes, I do think if a thread says “Open Spoilers” all of that - trailers, articles are fair game. Unless it is specified to the contrary. If the OP said that Open Spoilers are just for what is aired on the TV show and other content is to be spoilered then that would be another thing - however, in the case of Star Trek, you’d run into issues of are character backstories from other media (TNG, DS9, etc) allowed under the TV show only rule.