One of the things important for Germany to maintain a hold in Asia is to have an effective and important navy (Asia is not precisely the so relative nearer Africa) with the presence of France, United Kingdom and the rising power of Japan it is necessary to have an Asiatic Squadron of interesting size.
But Bismarck not envisaged truly to have a great navy, it was only after his dismissal that begin a new moment in the Germany History that saw an interest in have a big navy.
In fact Bismarck had a clear distrust in having colonies (he considered colonies a distraction in the for him the real necessity of Germany, to get an equilibrium in Europe that permited to isolate the revenge ideas of France), it was only the pression of commercial circles and public opinion if I remember well that get that bismarck agrees in giving a bless in having some colonies in Africa (and I think only after the Berlin Conference of 1884-85).
So, in fact we surely need a POD where Bismarck have a different opinion about colonies and navy or a POD where Bismarck is removed some time before of 1890, in any case it could a true tough POD to find.