Yen is disliked by Hongkongers for his pro-Beijing stance.
The 14 can apply for permanent residency in the country immediately.
Epoch Times is a staunchly pro-Trump outlet known for peddling misinformation.
The yellow masks had "FDNOL," which stands for "Five Demands Not One Less" printed on them.
Mainland Chinese authorities earlier told the lawyer he would have his license revoked.
Hongkongers accused Twitter of violating the US president's free speech.
The police came to arrest him at 6am.
The ex-lawmaker fled Hong Kong last December with help from Danish activists.