Given the timeline of just 4 months, I would expect 90% of customers not migrating in time. The percent of those who migrated to the new API after that depends

Given the timeline of just 4 months, I would expect 90% of customers not migrating in time. The percent of those who migrated to the new API after that depends on how vital this service is to them, it would be interesting to see the rate of lost businesses. I know that if a service provider did this to me, I would prefer migrating to their competition, all things being equal.