Meta's Delivery Estimate API drops three fields on October 27

On October 27, 2026, Meta's Delivery Estimate API will stop returning daily_outcomes_curve, budget_guardrail and estimate_dau, with no replacement and no error. The change applies to all supported Marketing API versions, including unversioned calls, so pinning an older version won't help.

• Three Delivery Estimate fields disappear on October 27 with no replacement
• Requests still return 200; the fields simply vanish from the response
• The change hits all Marketing API versions, including unversioned calls
• The story value in messenger_positions will also be silently stripped