This stuff you still need to discuss. It's just that the basics are often enough. But, in my experience, if you want less than 0.3 mm tolerance on your PCB outline or a component needs a certain soldering cycle or method, you better tell your PCB manufacturer and you better do it on the phone, they may or may not look at the drawings. Once we only accidentally discovered that an isolator in a medical device was soldered using a temperature profile that exceeded its maximum temperature and thus the isolation was no longer guaranteed by the manufacturer.

ECAD is way more standardized than MCAD for information sharing and version control, and at least has industry standard best practices. MCAD is still a wild west, with mostly proprietary tools used for version control (several thousand dollars per user per year) with no hope of interoperability. And each vendor that offers automated quoting uses a proprietary system, with a lot of manual inputs.

Granted, mechanical parts can be much more complex and it's easy to make unmanufacturable parts in MCAD, whereas ECAD is basically a stack of 2D layers. But still, as a mechanical engineer I am amazed at how easy it is to order a PCB or even an assembled PCB compared to ordering the simplest machined part.

I give it 2 years tops :p