They knew, the original investors just wanted a payout with someone else holding the bag. As more index funds blindly buys stocks, we will be seeing this more and more.
As far as I know (correct me if I'm wrong), indexes do blindly buy stocks but they only buy once a quarter or so (roughly) so unless they IPO at the exact "right" time, its not going to just grab it up right away. If its that volatile its going to be bought up after the significant losses happen, if it gets bought at all. Also the 90% loss is from the initial release which happens to private investors, mutual funds typically don't get into it until it's more publicly available (later stages), and this stock has only dropped ~35% since becoming publicly available.
Sorry, but this makes no sense. First, it was a de-SPAC combination so only two investors putting fresh money in and, it seems, all the SPAC IPO investors dumping ad quickly as possible.
Second, index fund buying would be a positive so not sure why that is mentioned here.
SPACs were not of interest for 20 years, anyone still contemplating has likely been turned down by everyone else.