I would argue that is still latent demand, just on a geographically larger scale.

If demand were met (globally) then adding a train line (or highway, or stroad) would have a neglible impact on traffic and business development patterns - because everyone can already get to their needs and wants in a timely and economic fashion and therefore has at most casual incentive to use the new infrastructure.

For instance a literal "road to nowhere" may 'induce demand' but only because there is unmet demand elsewhere.

Even as the world population starts to decline (expected in the 2080s according to the UN), cities are likely to expand for a while as people move out of rural areas. Which means that just population projections for your lifetime imply that your city will be growing in population for your lifetime. Therefore there will be more demand for travel over time (unless you build so much that you get ahead - good luck as this is expensive)