I can't find a specific example now, but every time I saw it mentioned on the Disney Parks Blog, it said the rose gallery room was only open for lunch. I'm very picky about grammar and wording in real life, but I definitely noticed consistency on all of Disney's official
Likewise, WDWmagic's
main site says the same thing. Also, lunch's capacity (546) is higher than dinner's capacity (340), which further supports the idea that one room will be open for lunch but not dinner. I think some people misinterpreted the wording (which has sparked some confusion on various sites), but to me it's clear that dinner guests will be seated in the ballroom or West Wing.