If the panoramas are the same ones, where you've just change the withe balance or change something to the image, just make sure the file has the same name as in GoThru (you can check for the file name under Edit, click on the sequence number, top right corner, on a thumbnail) and then upload the file back to GoThru. The new image will overwrite the old image and all you need to do is click on Google->Update and GoThru will auto delete from Google the old pano and publish the new one.
Your tour was fully map rejected, for cases like this you need to delete the tour from Google and then publish it back. Just updating does not do anything beside updating metadata for a map rejected pano. (that does not make a pano map approved)
@stéphane-de-greef The moderator supports only Google Maps, we are using Map Box in the Tools section so we mitigate the usage cost Google Maps API has.
I understand your point. The thing is right now our focus is not on the Moderator but on the Overlay Editor, and we have no idea when we will go back on the Moderator. But when that will happen allowing you to switching between OSM and Google will be an option.