No, the XBox360 is NOT getting the 1.3 update.So, by the way the original post was worded. Xbox 360 is getting 1.3? From a personal standpoint, that might be good, saying I have family members who use Xbox 360, while I use PS4 and PC. Although, I don't think the 360 nor the PS3 are powerful enough to run 1.3. That update is huge.
The point of this exercise it to help ensure that people who have save data on their 360/XB1 that they wish to continue using in 1.3 on their XBoxOne can do so.