Yup you changed your gears but did not alter shifting etc for your PCM and transmission. Your in a lower power band now than before so I would definitely data log it, and get it tuned.
It is not a problem and nothing is broken just by changing the gearing and not changing shift points, firmness etc to compensate for this change you may get more erratic behavior as it was previously tuned for a different gear set. The computer is expecting a different RPM range at a different speed, is how my dealer explained it.
Also if you have a pre June 10 build and not done the TSB 11-11-11 I would get that done because gears will make the shift surging issues and such more pronounced than before.