Initial claims are:
Claim 1: ABC
Claim 2: claim 1 + D
Claim 3: claim 1 + E
Nonfinal rejects claims 1-3 under 102 in view of Smith.
Applicant responds with amendment to make Claim 1: ABC+D+E, cancels claims 2-3, argues persuasively why Smith fails to teach D and also argues persuasively why Smith fails to E.
Since the amended claim 1 presents the combination of D+E for the first time ever, could you make an entirely new rejection (say, a 103, or a 102 with a new reference, etc.) and go final? Obviously you couldn't if Applicant just added D or E to claim 1 .. but in this case, did Applicant effectively shoot themself in the foot by combining these limitations for the first time when they didn't need to?
I think it's technically proper. But I also would understand why an Applicant would get upset at a final that did this.