Interesting topic.
As I understand it, "diaper dependency" is a theory that someone who not already completely UI, after an extended period of diaper wear, may increasingly and involuntarily use the diaper, with the risk of eventually losing voluntary control and becoming totally dependent on the diaper.
Many Internet postings suggest that a partial loss of control may occur over a period of several years of using diapers 24/7.
It is considered likely that the individual will not lose all voluntary control but instead will have decreased control (difficulty holding urine). if you have some voluntary control and exercise it by trying to pee in the toilet as often as you can, this should not develop into a problem.
Despite extensive research I have been unable to find a medical study that substantiates the diaper dependency theory - I did locate one which involved only a handful of very elderly nursing home residents and provided inconclusive results. Of course, it is not the sort of topic for which the diaper companies will provide research grants.
--John