Recall, an official recall, is a safety issue notice really. Its a legally defined thing in motor vehicle code. If manufacturer finds a defect, issue or feature affecting driving safety they have to notify safety authorities and get a recall issued. It doesn't have to have anything to do with, whether the product goes back to service garage or not.

Important point: Not every Tesla OTA update triggers a NHTSA (or other national road safety agency) official recall. Tesla has updated their cars plenty without recall notice. Only safety related issues get recall issued along with the OTA update.

Thus it is meaningfully, that they have so many software related (and thus OTA fixed) safety recalls. Each of those times is Hey, NHTSA, gonna have to admit, our software has a safety oopsie on it. Here is the paperwork, could you please issue us the official recall campaign number. Yeah software team already developed fix for it, it's all in the paperwork. We issue recall notice for drivers to check for the OTA to have gone through properly, that is all they need to do.

No maker wants to have safety recalls. It's bad PR. Makers have been fined plenty times for failing to properly inform agencies. One of the most famous is the Takata airbags. Where Takata got fined millions by first knowing and not telling their airbags had extra spicy unstable propellant exploding way too violently. Plus after firstly admitting to it lying to for example NHTSA about the vast extend of the problem.

So it matters, that even on "just a software issue" recalls are issued. The main point is public is properly informed. Lot of time it's resolved without great calamity. However this was exactly the lesson learned. Don't let makers hide issued, make them admit immediately so public knows and can take appropriate mitigation, before someone gets hurt. Also makes makers fix things quickly. Otherwise other priorities might override, since What they don't know can't hurt our reputation, like this is marginal issue. We can take little more time with this. Oh it takes 6 months to design fix with that small team. No worries. After all, no one knows. We have time. Except during that slow roll someone bumps into that "marginal issue" and gets hurt. Having to publicly admit immediately puts fire under their hind quarters. "Whole design department, stop what you are doing. We have safety recall issue. It went just public. Everyday company sits without being able to say No worries, we have solution we take flack. This is now priority number 1. This must be resolved yesterday, says the company board. Whatever parts or equipment you need, order it. Whomever you need to call, call them."