How should Adobe handle it?
Pantone support is a neglected feature that Adobe thinks most people should not be using.
* Do you pop up a UI saying "hey you're using it wrong, convert it" then run the risk that a user needs Pantone support and accidentally converts their files from Pantone and doesn't have a back up?
* Do you automatically convert their files and run the risk of getting sued when the user discovers the change?
* Do you automatically charge their Adobe account $10 and render the colors using Pantone?
* Do you eat the $10 for each user on the off chance they need Pantone?
* Do you eat the $10 only if a user ever opens a Pantone format file? The following week Pantone releases some asset free to everyone in Pantone format to boost their quarterly revenue?
They chose an option that makes it apparent to the user that there's a problem they need to resolve without embedding any controversy in their App or potentially harming user's file.