I don't know if this 'could' in anyway affect deeming regulations. It looks like the deeming regulations were 'finalized' May 5, 2016, so perhaps not.
"Republicans who hope to undo segments of Obama's legacy have a powerful tool to do so in the Congressional Review Act of 1996. The law will enable Congress in January to repeal, with a simple-majority vote, any agency rule completed after May 30, 2016, as Politico reported. After blocking any rule with that mechanism, the agency would be barred from enacting anything that is "substantially the same."
"And some Republicans are pushing to bolster the tool by enabling Congress to repeal groups of regulation wholesale, instead of dismantling it piece by piece."
Federal agencies push 'midnight' rule-making flurry under Obama
"Republicans who hope to undo segments of Obama's legacy have a powerful tool to do so in the Congressional Review Act of 1996. The law will enable Congress in January to repeal, with a simple-majority vote, any agency rule completed after May 30, 2016, as Politico reported. After blocking any rule with that mechanism, the agency would be barred from enacting anything that is "substantially the same."
"And some Republicans are pushing to bolster the tool by enabling Congress to repeal groups of regulation wholesale, instead of dismantling it piece by piece."
Federal agencies push 'midnight' rule-making flurry under Obama