When an employer is merged or purchased by another company in its entirety, the new company is called the Successor-In-Interest. This means that a new employer steps in the position of the original employer to continue the green card petition of its employees because the new employer assumes the entire ownership and liability of the original employer.
So the above situation is considered different from a typical Change of Employer where you leave employer A and join employer B.
This could be due to the fact that Successor-in-interest can take over the I-140 and GC process without the need to file a new PERM (if same job & location) however if the Successor-In-Interest does a EB2 to EB3 downgrade using a ‘New’ EB3 petition (in which case I-140 for EB2 still remains valid), they may be liable to do PERM process again. Instead if they do EB2 to EB3 downgrade using ‘Amendment’ to existing EB2 I-140 they can use EB2 PERM which means no need for a new PERM.
So in your wife’s case the attorney have filed EB2 to EB3 downgrade in October last year using ‘Amendment’ process and they are thinking that your EB2 I-140 can’t be used anymore for interfiling? I am not really sure about this. My understanding is that when doing downgrade using ‘Amendment’ process, the EB2 I-140 is valid till EB3 I-140 is approved.
Your attorney can confirm if you can still do interfiling and withdraw the EB2 to EB3 downgrade. Just discuss with them and see if you have this option available.
Any reason why you didn’t request premium processing for the EB3 I140?
I don’t understand why you would file for EB2 after your EB3 downgrade is approved as your PD is current in EB3. There is no need to file for EB2 unless the dates retrogress in EB3 but remains current in EB2 and there is almost a no chance of retrogress in near futurr.