This is actually a pretty big deal. I got a lot of text coming up, but the short of it is that apple requiring calibration/pairing and not offering the tool to independent repair shops resulted in these shops being forced to offer substandard results to customers because of issues with a part that costs 6-8 dollars. This often put people in a position where they need to pay 1000+ dollars to get their whole logic board replaced by Apple or pay a reasonable price for minor repairs and not be able to have their laptop sleep when they close it.
With the previous models using a nearly identical lid angle sensor you could simply swap in a new one and it wouldn't need calibration. With the apple silicon MacBooks, if you were to swap the display assembly or the lid angle sensor was damaged you would typically end up with a laptop that would not sleep when you closed the lid or would sleep at a weird angle along the path and wake up when fully closed. Only apple and apple authorized repair centers had access to the tool to calibrate an angle sensor. This is a problem because under Apple's system if there are any signs of liquid on the logic board you would be forced to either get a whole new logic board or decline all repairs even if the issue was just the sleep sensor and the only issue on the logic board was a water sticker going pink. For anyone who doesn't have a spare 1000+ dollars to tackle an issue with a 6-8 dollar part (likely cheaper through Apple's supply chain) independent repair is the only real choice. This tool enables independent repair shops to perform this simple repair as opposed to an extremely difficult repair to try to fix the original lid angle sensor. It also avoids them being forced to return an improperly functioning laptop to the customer if they find an issue with the sleep sensor after doing board repair or god forbid they accidentally damage an 8 dollar part and can't just swap in a new one on the house.
In isolation this tool seems pretty boring, but this sleep sensor issue has been genuinely worrying for the future of independent repair and what apple could do next along with artificially making independent repair seem far inferior to apple authorized repair. Someone creating a tool to solve the issue independently is a great sign that if apple tries to monopolize repair through artificial limitations then people can still find ways to work around them.
What do you mean added for non customers? The entire purpose of not adding RCS or supporting iMessage for Android devices is to create a worse experience for their customers if they interact with non-customers. Sure it likely drew more people to buy iPhones, but it's also arguably pretty awful for any society that plays apple's game rather than just downloading a cross platform app.