"With a federal lawsuit expected in a matter of days, states including Colorado, Iowa, Nebraska and New York are preparing to issue a joint public statement indicating they are still scrutinizing a wide array of Google’s business practices and may instead opt to join any federal case later, according to four people familiar with their thinking, who spoke on the condition of anonymity to discuss a law-enforcement matter.

The timing may serve to grant the states additional legal and political flexibility, the sources said. Some remain uncomfortable with the Justice Department’s approach to the Google investigation, while others fear the potential for a disruption in the lawsuit in the event that President Trump loses the 2020 election — a result that would shake up the federal government’s ranks and delay what is widely regarded as one of the most significant antitrust lawsuits in decades."

One of the side effects of the Trump White House has been forcing the close collaboration of states Attorneys General in order to accomplish anything at a national level. They've gotten pretty good at this; WA's attorney general has his kills painted on the side of his fighter plane:

Bob has filed more than 40 lawsuits against the Trump Administration, and has not lost a federal case. Judges have ruled on 21 of these cases. Washington state’s legal record under Bob’s leadership is 21-0. Twelve of these decisions are final and cannot be appealed.

I haven't looked nationally, but I'll bet other states are similar. If they join on with Barr, they have to

- Give Barr all their work product

- Surrender the direction of their suits to Barr

- Eat shit if Barr settles with Google

So no - there's no reason for the states to join the lawsuit when it is openly, transparently about Trump being a distraction and making your parents wonder the exact same thing. You can tell them that this is like Cartman showing up at the last minute and demanding Kyle make him leader and give him all the materials for their group project because he ran out of Cheesy Poofs.