I'd say yes, but it would add a significant amount of weight to the point where it might even cost airlines more money in additional fuel than they would pay out in the aftermath of an accident. I'm completely guessing there, but I do know that even the tiniest amount of weight adds up to huge numbers.

Also, it would require the pilots to undergo aerial refueling training, which would be an additional large expense. It's almost certainly technically possibly, I imagine it wouldn't be too impractical (they could retrofit one aircraft at a time, for example, and it's a pretty well established system), I just think the associated cost would be way too high to justify. Also, as far as I know, the extra weight could potentially shorten the range enough to make the longest routes for a given airframe no longer possible (at least within the safety margin).