IF, big IF, it becomes federal trust land the federal government owns the land and everything on it and in it. The State, any affected municipalities and utility companies will probably have to get new right of ways approved by the Secretary of the DOI through the BLM (Bureau of Land Management).
Act of March 3, 1901 (25 U.S.C. § 311) authorized the Secretary to grant rights-of-way to a State or local authority for the opening an establishment of public highways in accordance with State law through Indian reservations and allotted lands.
On other trust lands everything that was maintained continues to be maintained by those that had been doing so, generally along with agreements by the tribe and federal government. There may be municipalities that dissolve and counties that merge for the obvious reasons. You can't do something with nothing. There are a myriad of issues and questions which will likely result in the State getting more lawsuits filed against it than it just had dismissed. The State could use sovereign immunity to block them, but it cannot do so against a civil rights lawsuit. A class action may well cost the State more than it allegedly saved.
Federal water quality standards are nowhere near as high as the State and an example of that is, if the Village of Union Springs were under federal standards, they would not have had to build a $250,000 stripper building. In fact if Union Springs were in Pennsylvania they would not have had to build it. The residents would just be drinking trichloretheleye without knowing it.
Under the Winter's doctrine tribes have a right to use as much water as they want to suit their needs. So if they build a casino or strip mall or golf course, they could diminish the water source or overwhelm the sewage plants with no recourse.
A friend has a cattle ranch in South Dakota with a neighboring tribal casino. The sewage from the casino forms a river across his property. That is shown in the video which accompanies Elaine Willman's book Going to Pieces.
The settlement rammed through by Prince Andrew was not even finalized when the counties were intimidated into voting on it. It was another one of those, you have to pass it to see what's in it and details will be worked out later.
So you might better present your question to the State. None of this was addressed in the settlement.