This is quite likely as a plotline, really. Only they haven't cast Brian Brophy yet...
As for Data not being replicable, we don't really know that. Nobody wants to replicate Data, especially not in "Measure of a Man". Maddox wants to understand Data, so that he can build further androids who are not Data. And this requires dismantling Data, not duplicating him.
Perhaps every single bit of Data can be replicated just as easily as the totally alien probability-skewing machine in DS9 "Rivals" was, at the push of a button in a standard food replicator. But Maddox was facing ethical problems in ripping out any such bit for study or replication. And if he replicated Data as a whole, he would be facing the same problems with said copy!
Perhaps F8 and his brethren are created through replication, but of a pattern android that is already what the defense disingenously claimed the eeeeevil Maddox wanted his androids to be like - mindless slaves who would not object to being even more expendable than flesh-and-blood minions. How one would achieve this pattern android is the question. In the Asimov-verse, positronic brains could not be easily customized; a working model had been found essentially by chance, and even minor adjustments just tended to crash the product, while major ones such as removal of the Three Laws required such an ungodly amount of work that governments would fall before such work could be completed.
We have no idea whether Soong's positronic brains could be easily modified. They were obviously named after Asimov's, in-universe - "Datalore" is pretty explicit about it. But just as obviously they are not related in any practical fashion, because in-universe, Asimov's brains are mere written fiction that has no scientific basis, while Soong's brains are working technology that obviously has a basis.
However, we know it's trivial to tell basic Soong brains to do unusual things, such as turn evil. Lore and Picard play tug-of-war with Data's easy-to-reach ethics switch in "Descent"; welding it in the "Evil" position as a factory setting should be simple enough.
What nefarious use would F8 androids be? Starfleet already has all the slaves it needs, in the form of holograms that have no rights whatsoever unless a sentimental owner grants her pet program some. Why go back to a primitive android army if you can deploy advanced holograms?
Or could the F8s have a non-nefarious goal? Perhaps this is where dying people are going to put their souls in from now on, Ira Graves style?
Timo Saloniemi