I actually think it's a good thing that Kings Hall is opening a rare room, I will deffo start going again for this reason alone (though hoping they will allow record sales in rare room cus I really don't wanna sit on the balcony listening to the main room playlists).
I don't see why you worry if it will affect your promotions Phil, I'm certainly not worried that it will have any impact on Bidds and it's only 4 miles away from me.
As well as it's strong support from nationwide oldies fans, Kings Hall attracts a lot of local support from old soulies/mods/scooterists, many of whom go nowhere else the rest of the year.
I see such faces in there that I ain't seen for donkeys years, as well as guys I've worked with who go along hoping to hear Motown and James Brown etc but still have a great night cus of the atmosphere.
The fact that those who travel to more upfront venues may start frequenting KH again for this 3rd room doesn't mean (IMO) they will stop attending the venues they used to to hear such tunes...after all, it's only on 4 or 5 times a year.