you could make it that inspiration is a reroll, but if you choose to use it and wouldn't otherwise have disadvantage then it counts as advantage for the purpose of features that ride off advantage (such as sneak attack).However, it would remove the fact that Inspiration gives actual Advantage, not just a re-roll, so a rouge couldn’t get Sneak Attack with it, for example.
Plus, with the more frequent gaining of Inspiration in the update, forgetting you have it may be less of an issue.