The party in power in 2003, has announced in their election manifesto, to end personality cult.
They had come to power for the first time, after having been in opposition for long ( ever since independence) due to personality cult of the first President. It was the effigy of second president appearing on coins that resulted in continuation of personality cult and led the opposition to announce that they will end the cult.
However, on getting elected, they started to work on that cult development and to ensure the effigy, they announced 40th Anniversary, which is a non standard. They could not have waited for Golden anniversary. Thus controversy started and coins were withheld.
A similar( not exactly same) is case of 2 Balboa of Panama which was minted but whose release has been withheld or Nigeria set which were designed but never minted. Makes very interesting reading nevertheless.