To be honest, I didn’t think it was likely that a team other than the Astros would lead the AL West in June. But baseball is a hard sport to predict. The strangest things can happen. Like, the Mariners leading the AL West in the first week of June.
That said, the Mariners’ current lead over the Astros is one game. If the two-game series goes the Astros’ way, then Houston would lead the division by Wednesday night. And the overall indicators still point the division to the Astros’ favor. For example, Houston has the best run differential in baseball at +122.