1. This law is extremely broad and covers any "digital electronic equipment". Since everything has a computer in it nowadays, it's hard for a person to even understand what industries this covers.
This is unnecessarily much broader than the original intent. Right to repair was mostly pushed for by computer repair shops, who mostly work with consumer electronics. The New York lawmakers acknowledged there was some problem with this, that's why they excluded everything medical or automotive. But every other industry is still effected and it will have unintended consequences. They excluded only cars and medical devices, but did they still intend for this to apply to boats, planes, construction equipment, missiles, building access management, even pipelines?
The Colonial Pipeline must have some "digital electronic equipment" that controls it. How likely is it that if all the maintenance manuals for that stuff are released, people will find some security-by-obscurity there? Computer repair shops are not going to repair oil and gas pipelines, so is there any reason these manuals need to be made publically available?
2. Everything this law requires is going to be made public, it won't just be for independent repair shops, and that may not be in the public interest. The law acknowledges that for security-related information, there may be a reason not to make it publically available. It says that "such documentation, tools, and parts may be made available through appropriate secure release systems." But they can't actually enforce that. The law says that manufacturers have to provide these maintenance manuals for free to any "independent repair provider", which could be a 1-person company, and the right to repair folks already stated they want to dump everything online. So all this confidental information will get leaked immediately and there's nothing the manufacturers will be able to do about it.
3. Security. For electronics, security-by-obscurity is all over the place, you can find it everywhere. Devices always need some privileged mode for things like testing, administration, or maintenance, and it's hard to do that securely on processors that are as cheap as possible for business reasons.
Consider e.g. building access control, like the keypads on apartment buildings. These have a need for someone to be able to unlock the door in unusual situations, e.g. for maintenance, building administration, or for firefighting. Instead of a TLS stack, they probably have some obscurity-by-security keycode, like pressing #12345 to enable the maintenance mode. This would be documented in a maintenance manual and not provided to most end users. When the right to repair folks dump this manual on the internet, it's going to help criminals a lot more than repair shops. Repairs to apartment keypads are rare, but thefts from apartment buildings are very common.
This same thing will happen with a million other devices that no one has thought about yet. If the manufacturer created some features that the user is not supposed to access, there's probably a reason for that. But all this stuff will be recorded in maintenance manuals, and making it public won't really benefit users as much as it will harm security.