The VCs don't "owe" money to the startups: they "buy" equity with their money. The VCs aren't "out" the money deposited by the startup at SVB; that money was already exchanged for equity in the startup.

The VCs aren't happy because they and the startup both expected that the money-equity exchange meant that the startup would have working capital, so potentially the value of the equity that they got has fallen. This is a problem for both parties.