First, turnovers don't just happen. Fumbles for the most part are random. Interceptions are usually a result of an error, either mental or physical, and when they happen in abundance are usally attributed to the QB.
Second, Stafford is playing better now than he did when he had Megatron. Shocking a QB plays better with more game experience. Has TT made a huge leap this year to being a better QB? No, I don't think so but maybe he has made a little skip forward. I certainly don't think he has regressed. Wilson got better with experience. Fitz, Kaepernick, RGIII all got worse the more they played and defenses adjusted to their games. I suspect the same is going on for the Bills and TT.
I have no idea if he will get better, stay the same, or regress. I don't think accuracy improves for any QB. EJ's hasn't. Wilson's is very good. TT misses too many easy throws. But decision making can improve. TT already protects the ball. He makes plays. His legs will make up for at least one or two bad throws a game. He just needs to cut his mistakes in half and make three or four more good throws per game. Those added completions will keep drives alive, win the field position battle, and generate 3-10 more points per game.