The old S&D served three major national venues, and the New S&D will do the same. One was there even in 1966, one has sprung up since, coincidentally on the route and the third was actually inspired by the S&D. All will be served directly by the New S&D.
First off is the Bath and West Showground at Prestleigh. This actually is already rail served, but only internally and on the 7¼" gauge. The Bath and West Show is a really big event, and is on at the moment. As road traffic falls it will, if it plans to survive, need a rail link. This could either be a standard gauge branch off the main line, or a narrow gauge feeder route that also serves the showground internally. There are regular events at the showground, many of which attract thousands of people, so the route would be opened many times a year.
Second is the Great Dorset Steam Fair. This was inspired by the S&D and the operating company is currently looking at an internal narrow gauge permanent railway to service the site in future years. No doubt the wheel will turn full circle and the restored S&D serve the site, again either with a standard gauge branch from Blandford or an extension of the narrow gauge internal railway to a new S&D station.
Lastly is the Glastonbury Festival. This is one of the most famous and important music events in the world. Currently special trains are run to Castle Cary during the festival with onward transport by buses (LOL!) Interestingly the old S&D Highbridge branch trackbed currently serves as an internal road within the festival grounds - so building a station within the festival site will be a doddle.
Railways in the future will serve the areas they operate in far more intimately than the old lines did with many branches, tramways and ultra light rail systems connecting to the main routes. The S&D will hopefully be a leader in this new form of community transport, linking communities to each other and to the wider world.