EASA yanked out certification of Russian aircraft as part of the sanctions.
This includes certifications for the Tu-204, Sukhoi Superjet, Be-200, Ka-32 helicopter.
China just needs to increase production and make more C919 parts in China. US/EU certification is pointless in the short term. These certifications do not matter for sales to Southeast Asia, South America, or Africa.
China just needs to crank these aircraft out, make sales, and establish a support infrastructure.
What this proves is the EASA certificate is more a political certificate than an aviation safety certificate. The aircraft is no less safer after these suspension.