This has happended before. See below as reported by someone. Your choice.
>>>>>>>>>>>>>>
So that will mean that when you send in your new 140, they will ask the
employer whether you want EB2 or EB 3. Then the employer will say EB 2. Then
they will revoke the currently approved one and adjudicate on the new one.
I went through this.
"05/09/2006: Traditional Practice of Filing Two I-140 Petitions Based on
Same Labor Certification Under Review by USCIS HQ
Traditionally, the USCIS has been allowing the employer to file EB-2 and EB-
3 petitions using the same EB-2 labor certification approval. However, the
NSC indicates that this policy is currently reviewed by the USCIS HQ and
may be revisited with the potential consequences of termination of its
traditional practice and policy. It is another bad news.
Pending the policy changes, NSC will request the employer to chose one I-
140 petition out of the two I-140 petitions and the second I-140 petition
will
be held in abeyance until the HQ policy is fixed. Bad news after bad news.
Filing two I-140 petitions by the same employer using the two different
labor certification applications: No problem. NSC will adjudicate both. "