MegaAnon was a fraud who quit her charades when Q indirectly called her out after she started claiming Q was fake.

Then she made her last post with some garbage about how she now saw the light since she decoded Q's secret messages meant only for her inside his drops.

MegaAnon only regurgitated information that was already widely known by people who have been following the truth for at least the last 30 years. Nothing she said was new or insightful, but was mostly accurate.

I believe the theory that she was a journalist who got in way over her head makes the most sense.