i think the true answer is, "it's impossible to know".  a loss of that magnitude would wipe out alot of Bitcoin's most ardent supporters, eliminate the perception of SOV, and could set the community back 100 yrs.  in that sense, the BTC price could tank.  i know i wouldn't trust crypto devs anymore in my lifetime if i lost scBTC from that scenario.  or, yes, it could "make all our BTC more valuable!"  that's certainly the conventional thinking around here.

the difference with your gold example is that i doubt the Chinese had any idea a Spanish armada ship laden with gold went to the bottom of the Atlantic.  today, we have the internet and the media would be all over it.