Stress-test a legacy plan sunset before migration charts, grandfather clauses, and customer letters harden into what every renewal will quote.
Legacy sunsets fail when the timeline invents capacity support never had, when grandfathering dual-counts the same account as migrated and as protected, when pricing still shows retired plans on public pages, and when finance cannot show who owns win-back after forced moves. A neat sunset slide is not evidence.
What to put on the table
One sentence for why the sunset exists, which plan cohorts and regions it covers, who owns migration tooling and customer comms, and the rollback trigger if churn or support load past a named threshold. Attach the cohort list, sample migration paths, letter drafts, and the measured path from notice to completed move. If product, finance, and success disagree on which customers are truly movable, stop and reconcile first.
Name the decision you will make if the stress test finds nothing new, and the delay criteria if any cohort lacks a named migration owner or a verified pricing path.
Pressure map
- Timeline fiction: dates that look firm while tooling still cannot move the largest accounts.
- Grandfather blur: exceptions that still say "case by case" without a named role.
- Pricing theater: public pages that still sell the plan you swore was closed.
- Comms lag: letters that trail the price change customers already saw on invoice.
- Revenue silence: cliffs that land without a win-back owner or measured lag.
Optional counsel seat if contract language binds the notice period. Optional support seat if ticket volume will spike on day one.
How to run it
Feed Pingpong the draft sunset plan, cohort math, and open risk list. Early passes steelman the design. Later passes attack from finance, success, support, customer, and skeptic seats. End with a pass that turns surviving objections into clearer owners, a timed practice migration, or a hold. Delete invented "customers already want the new plan" claims and dual-counted migration rates.
Ask finance and success seats to price the behavior the published sunset will invite. If day-one letters promise one-click moves while the last dry run stranded mid-market accounts, buyers will treat the plan as false. Write the intended cohorts, the tooling checks, and the language you will refuse, then attack whether trust still holds under that discipline.
When the sunset coincides with a packaging change or a region launch, force product and billing seats to map every claim that still assumes the old plan codes. Invoices, partner portals, and sales decks count. A sunset that looks clean in a PDF while checkout still offers the retired SKU will fail on the first renewal wave.
Force a day-after narrative: what happens if a large account screenshots mismatched pricing, if migration tooling fails overnight, or if support cannot clear the queue. If those stories are stronger than your mitigation plan, fix the package before you announce it. Related: stress-test a product sunset, stress-test a billing change, war-game a packaging change, pretend you are the customer success lead, and the war-game decisions hub. Process: how to run a Pingpong.