This is not a bad solution in my opinion, if maybe a little inelegant. Reminds me of the solution of adding a splash of soda water, but I think this would probably taste better. The only downside is you don't have that honey aging in the bottle alongside the rest of the Mead, which is kind of a bummer and might cover up some of the nuanced effects of adding. But I'm just speculating.
Edit: Not the only downside rather, seeing how it is more work to have to measure and add more honey and mix it in rather than just popping open a bottle and enjoying.