It is a little hard to understand. Usually a culture wants to preserve its great art for the generations to come. They are telling us that for a classic like My Fair Lady they are preserving the vehicle into which other actors may be used, but they are not preserving the original production with the actors who originated and defined the roles.
Early television was mostly live and not preserved, but as soon as the means was there, everything was recorded. That is why we can look back proudly to the 60s and watch an episode of My Mother the Car.
But really, there is all that value sitting there and, from the little experience that I've had subscribing or donating, they always need money.
But, hey, Roundabout streamed She Loves Me and now BroadwayHD has it (and almost nothing else). If Roundabout is in such bad shape financially, nice chunk of change for Cabaret with Emma Stone (according to Google Search the highest paid actress in the world).
Of course fifty or sixty others, like the actors, would want a share of the loot, but greed will find a way.
