I clicked on their 'Platform manipulation' link to find out what they mean by that phrase. Early on it says:
"We want Twitter to be a place where people can make human connections, find reliable information, and express themselves freely and safely."
I don't see how bulk-created accounts are consistent with that 'mission' statement. What kind of 'human connection' might result from a bulk account someone paid Twitter to create? How 'reliable' might info from a bulk account be? Why else would someone create a bulk account, except to manipulate people?
Appears they're blind to their own hypocrisy? Further on, at the top of their manipulations list they mention "commercially-motivated spam, that typically aims to drive traffic or attention from a conversation on Twitter to ..."
Yeah. Uh, the Twitter feed contains a constant gush of paid-for spam that is intended to do exactly that.