That depends who you think will want to go to organ recitals! I agree that the obvious core audience will find noon on a Sunday inconvenient, and it might be argued that it is more important to retain the existing audience than to find new ones. But I am a little uncomfortable with the assumption that organ recitals will be attended only by other organists and churchgoers. Besides the RAM Bach cantata series has, I understand, a well-established regular audience of music-lovers. The recitals you refer to seem to be part of that series, so it is to be hoped that the regular audience will go to those as well as the cantatas, attracted by the implied guarantee of high quality. I may even get to some myself.