They won't grow to be anything, because they were constituted on the wrong basis to begin with...
A Marxist-Leninist party is formed on the basis of the demands of the times, as the fighting detachment of the working class, and the political expression of their aspirations; The APL arose because a bunch of tweens on the internet really thought Marxism was awesome, and thought it'd be cool to form a club. That's it.
Real ML parties begin by building practical organizations on a definite basis, and orienting their journalism and periodicals towards the class to build social consciousness.
The APL began by spending the next four years discussing the historical minutia of the cold war, and only ever speaking of socialism in the most abstract hypothetical sense, with premature delusions of grandeur as their foundation (i.e. what are we going to do after we win?)
This is why the APL will never grow into anything, nor will any other American "Communist" party out there today ( with the possible exception of USMLO, but they have their own problems as well). All of them were also formed on the " I'm a commie, you're a commie too; let's have a club, and build a fort!" mentality. They still have yet to make the concerns of the class their own, and they still have yet to provide leadership to the class in it's initiatives, or build anything resembling workers organizations. When they do pay attention to the present, it is always looking over-seas with that "revolution everywhere but here" type of mentality...
They are not a working class organization, and this will be their downfall.