There are also accounts by Xenophon. And I'm aware of the limitations of citing Plato's accounts, but that doesn't justify leveling any accusation one can come up with. Also, the satires of Aristophanes hardly count as historical evidence.
Neither of the other two sources you provided say anything about Plato or Socrates being complicit with the regime or guilty of genocide. In fact, it seems like they had some animosities towards the thirty tyrants.
Where are you getting this claim that Socrates was found guilty for the Athenian genocide? It says right here (https://en.wikipedia.org/wiki/Trial_of_Socrates) that the charges were impiety and corrupting the youth (by encouraging them to question their elders).
The impious acts cited were "failing to acknowledge the gods that the city acknowledges" and "introducing new deities" (apparently Reason (διάνοια) was a deity in their view...)