Andreessen stayed in touch with Wylie up until the story broke in March 2018, according to one of the sources. However, there was supposedly no "follow-up" to put Wylie's information to work.
Andreessen's venture capital company, Andreessen Horowitz, has declined to answer questions. In a statement, Facebook said it wasn't aware of the data transfer to Cambridge Analytica until December 2015 and "took action," but didn't say when executives were aware.
The leak (if accurate) doesn't guarantee that Mark Zuckerberg or other executives knew what was going on, but it could fill a gap in the timeline that has remained conspicuously blank. It would also raise questions as to why a major board member had talked to Wylie roughly a year and a half before Cambridge Analytica's data abuse became public knowledge. Whatever the answers, it's not a good look when Facebook is already grappling with investigations into its data handling.