Tbh I think they replaced Maikelele for Allu because the latter is a much more of a complete player when compared to Maikelele.
Allu didn't mind to pick up a rifle and work with that - very well in fact - while Maikelele couldn't.
Then there's the consistency factor; they're both good players but Allu is more consistent.
I think this was Allu's move/decision not to stay on NiP, rather than NiP releasing him, and who can blame him? It was the right choice, if you ask me.