At the present time (Sept 2022) MailChimp is one of the many domains which are blocked by the Great Fire Wall (GFW) censors within China.
Theoretically, it should be possible for your email to still reach the intended recipients in China provided:
a) Links to any resources hosted on MailChimp are removed (downloadables, images)
b) Your email text does not contain references to any politically or socially sensitive topics.
In reality, it might be simpler to just use a different email marketing provider.
SendInBlue, ConvertKit and AWeber all offer free plans, and none of them (for now) are blocked by the GFW. It would pay to double check with Comparitech or similar tools to see what the current status is.
Keep in mind also, that for cultural and historical reasons, email is not as widely used in China as it is in other countries.