In theory yes, but remember this? Airlines keeping tax savings for themselves
But remember all the times airlines have had price wars?
Whether or not cost savings are passed on to consumers in whole or in part depends on a complex set of factors including the corporation’s need to show earnings to please investors, the nature of its competitor’s pricing dynamics, and so on.
The most important factor is the bottom line: will cutting price juice demand and juice it enough to provide a certain profit margin?
That varies.
But generally, over time, when every company gets the same opportunity to cut costs, at least one will decide to compete on price and, hence, the downward pressure on pricing begins and lasts until demand at the lower price wanes anyway.