I agree with that too. It is not often you see typical CB types playing as fullbacks anymore. At least not at the top level. Last I can remember is players like Vertonghen, Rojo, Blind, Mathieu, Smalling, Boateng. Don't see that as much anymore, and teams might be more inclined to have two smaller attacking fullbacks instead of a makeshift CB playing there due to the general importance of the position. Obviously not everyone has to be amazing in attack to play as a fullback at the highest level, but they have to at least contribute in more aspects of the game than before. They are a lot more involved now I feel and so it will fall on if they are consistent or not in both defending and attacking and that is what will separate them.
I also see a lot of "attacking fullbacks" that doesn't impress me much. Some of them frustrate me like Zaha used to as a winger, capable of some sick things but just so inconsistent in their overall play. I think it's important to separate because otherwise we might put to much value on a bad winger playing as a fullback perceived to contribute in attack due to flair, and undervalue other well rounded fullbacks. To me the expectation of fullbacks haven't changed that much in reality, it's just a matter of the players at disposal and I think if a younger Sagna played for a team currently he would be as highly rated as he was a few years ago. Wouldn't get picked ahead of Alves just like he wouldn't back then, but ahead of a Clichy, yeah.
Damn, went a bit off topic. My bad. I want to see more from TAA before I'd label him a world class fullback honestly. To me, some days he looks unbeatable but other days he is doing some pretty weird stuff man. He is very young so time is on his side and the talent is obvious but to me he still has some distance to go. If he just stays at his current level it wont carry him through to have a world class level career, needs to improve in a few aspects but I see no reason why he can't do that.