That's right.Not exactly. The 2017 agreement is more of a programmatic document. The actual air worthyness certification of a particullar plane is still not shared. For example, China's ARJ-21 has been flying in China for years, but FAA have not certified it. The 737 max is first grounded in China by CAAC, and CAAC recertified the max much later than FAA did.
It's more a problem of politics than something of technology.