回複：回複：回複：回複：回複：回複：你的 F2 COS CASE被DENY了。你沒有COS成功。你現在的身份任然是H-1B。

Let me give you an example: An F-1 OPT student got H-1 approval which is effective on Oct. 1, but the employer does not hire him eventually, and withdraw the H-1 on Oct. 2. Thus, this student has no legal status because his F-1 (OPT) status was overridden by the H-1 on Oct. 1, then the employer withdraw the H-1. This kind of case is always reminded by the immigration law every year to the F-1 students. It seems your case similar to this case though I am not very sure.  In your case, USCIS approved your F-2 first, then denied it later after you requested. So, when you F-2 was approved (it was effective at the same time), your H-1 was overridden. Thus, the withdrawal of F-2 later does not automatically result in the H-1 reinstallation.  This is just my personally opinion for your reference.

I still suggest you to get the H-1 visa to be completely safe, but up to you, anyway.