What I'm saying is that these people have served in and participated in the decisions of the Obama administration, so they will have to answer for the outcomes.
As far as actings, I think the GOP can construct plausible or better cases to reject them by vote of the senate. If that were to happen, they could not serve. In Minnesota during the recent squabbles over emergency powers of the DEM governor to address covid, the state senate with a 1-vote GOP majority, rejected 2 of his appointees who had each been 'acting' for over a year. I wouldn't put it passed Mitch McConnel to orchestrate such an outcome if he felt the issues lined up in their favor.