Alternatively, lay-offs could be focused in companies who are profitable but with poor cash flow and who suddenly become insolvent. Earlier stage companies typically rely less on incoming cash from revenue and more on cash reserves from investment. Plus, investors have targets to meet on investments. They’re going to get more risk averse but they can’t stop investing for 6 months entirely.

Reading this thread I think you're mostly right, but there are stories here of people in established companies in hard hit industries (event planning, hospitality, etc) that are also getting laid off.