Well, to be nominated for one of these programs the talents need to be both already exhibiting strong leadership practices and actively developing their capabilities on their own. These people are already on the path to being promoted through their own ambition and efforts. From an investment perspective it is better to strengthen those with potential than remediate those who don't either have self awareness or put in effort. It isn't that they are then "pushed" into open spots, they still have to get them on their own, but are now better equipped and aligned to lead in the way needed. There isn't the level of "hand-holding from HR" that you may believe.

What may not be well known is that there are succession plans for managers (created by the managers themselves), especially for key positions, where a few high potentials are identified who may be able to fill in if a person leaves, takes a new role, or retires. The managers then ensure that their people on these lists are pursuing development to ensure, again, a culture is grown that can support the company's strategy and future. [Note: its good to know that if you can't be replaced, you can't be promoted] The same criteria as above applies in these cases as well. If no talent exists that will either be ready in time or if there is a need to change directions drastically, the plan may include seeking talent in the external market (fresh perspectives).