I’m not sure how much legacy code is written for contact apps in smartphones. But given the amount of tweaks and changes apple and Google make in each of their releases I would expect they wouldn’t have any problem integrating this feature.
Also you mentioned legacy code, but why T9 dialing isn’t a thing anymore coz that would be available if they were simply extending from legacy codebase.
Don’t underestimate the legacy code. There’s a reason we avoid it.
I’m not sure how much legacy code is written for contact apps in smartphones. But given the amount of tweaks and changes apple and Google make in each of their releases I would expect they wouldn’t have any problem integrating this feature.
Also you mentioned legacy code, but why T9 dialing isn’t a thing anymore coz that would be available if they were simply extending from legacy codebase.