This 1000% because you know for fuck sure that some dev in the corner of a building that’s going to be the last holdout.
Start planning now with an implementation plan to complete a few months before the contract is set to expire. Plans like these often hit bumps and delays.
Once you’re down to the last 5%, tell them “Join or Die”.
Short term is all that matters. Did the line go up this quarter? Then they’re good.
Killing the product is the future CEOs problem.