Hypothetically, there are situations where the novelty and excitement of a de-extinct species could act as a “flagship species” and actually attract public interest or funding to a conservation project.
There also is an interesting phenomenon where even just the possibility of having a management action such as de-extinction may change how conservation problems are formulated.
Conservation management currently aims to do the best it can, while operating under the constraint that biodiversity is a non-renewable resource. With this constraint we can apply theory that is used for managing the extraction of non-renewable resources like oil or diamonds to determine the best strategy for management.
However, if extinction was no longer forever, the problem could be considered as one that would be managing a renewable resource, like trees or fish.