In the meantime, ULA continues to use the Russian RD 180 engines as usual.
As of last month, ULA only has 29 RD-180 engines left for its Atlas 5 and all of those are booked so the BE-4/Vulcan setup is kind of critical and the clock is ticking. NASA and USSF can’t solely rely on SpaceX (though they really can) when performing risk mitigation so BO will get a trickle of money from the government in hopes of getting the BE-4 to an operational state.