So black teas are a very common thing to add to meads as they contribute tannins which can help with mouthfeel and balancing acidity of the final beverage. This tea in particular (Lapsang Souchong) is a smoked tea and so as well as adding tannins to the mead, also contributes as wonderful smokey flavour. My inspiration for this mead several years ago was to make something that had a similar flavour profile to a nice peated scotch. The maple syrup was allowed to fully ferment out to leave just a subtle woody-ness and it works in conjunction with the tea and oak spirals I aged the mead on to provide a pseudo-barrel aged taste to the final product.

Gotta try coke + coffee

Yeast will eat away all the sweetness from the syrup (unless the max ABV is hit) so syrup will end up tasting way less (and different). It might be much more normal tasting than you'd think.