Unfortunately, these are agency rules. Congress can intervene, but only with major legislative action, which is unlikely. There will be hearings and Senators will express great concern, but the Administration will probably be able to do whatever they want. If anything slows this down, it will be the courts.
The courts have truly been the last line of defense.
Congress being neutered is not an accident, hopefully it will be less fucked if the power balance shifts.
And as the OP is inherently political in what it's calling out, that is not the motivation -- it's the science. I get the fact that in the end, everything's political but partisanship itself is a cancer on the body politic. Just as we seem to be in late-stage capitalism, we are entering late-stage democracy. It pains me that we effectively arrive here by choice.
If Congress wants to earmark that money for a particular purpose it can enact that into legislation. If it wants to empower the executive to make the decision, they can do that too.
Those are the only people who get to decide. Congress can’t turn over the expenditure of taxpayer funds to people who aren’t politically accountable.