Ask HN: 20 months post-Seed, no Series A, safe to assume <3 months runway?

If a startup raised a standard Seed round ($3M) in mid 2024 and hasn't announced a follow-up round by until now: Is it mathematically possible they are still alive without a bridge round? (Assuming SF/NY burn rates). Does a quiet pivot to custom client work usually signal the end? trying to gauge the viability of a company based on these public signals alone. Is this a classic Zombie pattern?