But every regulation, manual, procedure, etc. document that refers to 'recall' would need to be changed and republished just to change the term. Manufacturers would need to change their policies, procedures, software, training materials as well to reflect the simple wording change. And, since there would be no change to how manufacturers address and remedy the issue, the change would essentially be cosmetic.
If a recall required manufactures to actually come in contact with the vehicles, then making the change to simply permit an OTA update would eventually result in cost savings. But OTAs are already permitted, so this would simply be a wording change.
What would be modernizing the actual procedures. As it currently stands, you will get a letter from Tesla in the mail in April formally notifying you of the recall. By that time, probably 90%+ of cars will have already received the OTA that fixes the issues, making the notice somewhat superfluous. Perhaps it would be more efficient to send notices only to owners who have not installed the necessary OTA. Better still might be to notify customers using other means, such as email, notification via the Tesla App and/or pop-up panel on the car's display. In an increasingly digital world, getting a paper notice in the mail is become a quaint anachronism.