Not going to happen. Oakland is going to build a privately funded park downtown at Howard Terminal or if that falls through the Coliseum site.
I doubt Vegas is going to spend more public $$$ on a domed ballpark after giving the Raiders $750M.
The A's are trying to buy the Coliseum site for $135M. They want to do a redevelopment there regardless of where the ballpark goes. The A's obstacle of getting a park was the Raiders. Both teams wanted to develop the Coliseum land(The Raiders also wanted $400M in public $$$). Before the Raiders relocation was approved Roger Goodall asked the mayor to do an early termination of the A's Coliseum lease and give the land to the Raiders. She replied back that doing that was "problematic".
Raiders' move to Las Vegas looks like a certain bet
The Raiders themselves in the article above admitted the city picked the A's and there was nothing wrong with that.
On the day the NFL announced the relocation of the Raiders to Las Vegas one hour after the announcement the Oakland A's team president came down to city hall along with the team mascot Stomper to raise an Oakland A's flag over city hall(signifying the A's victory over the Raiders).
Oakland Mayor Literally Raises A's Flag Over City Hall An Hour After Raiders-To-Vegas Vote | East Bay Express
Right after the Raiders announcement the A's went with a "Rooted in Oakland" marketing campaign.
'Rooted in Oakland': A's Committed to East Bay
Team president Dave Kaval expects with a new ballpark the A's will be in the top quartile in spending on players.
Rooted in Oakland: A’s president Dave Kaval provides hope
Oakland isn't like Tampa where you need a bunch of public $$$ since the market would be barely passable with a new park(though much improved by Tampa standards).
The only obstacle left is passing a Howard Terminal environmental review. The legislature passed a bill last month to help the A's streamline construction.
Legislature passes bill to help Oakland A's streamline construction of a Howard Terminal stadium