But the "secondary's for founders" is not that unusual - it's typically used as a tool by VCs who are in competition with other corporate development opportunities.
AKA Clubhouse had several suitors for acquisition (including Twitter it's rumored) but Andreesen added a few million bucks of liquidity for the founders to bridge the gap between "guaranteed liquidity" vs "non guaranteed but potentially greater upside" (1)
But then of course you have all sorts of eggregious examples over the past several years of Johnny Boufarhat @ Hoping taking $100m+ out or infamous Adam Neumann pulling out $700m+ from WeWork(2)
(1) https://www.forbes.com/sites/alexkonrad/2020/05/15/andreesse...