Sometimes they do change thing because they stop getting a particular part. For instance in 2005 Jan I got my Xli and the surprise was RPM meter (It was only given in Gli at that time), second surprise was remote control for cassette/radio (it was only given in Gli). I asked the dealer that how come RPM meter has been given in this car. He said Sir woh meter khatam hogai factory abb new lot ma saaray RMP walay arahay hayn. Note: rear lights were not changed then to LED, nor room cooler type grill was there.
Given new features would be more beneficial to IMC as it will increase the price for those features. It would make more profit per unit as well as increased sales further.
It does not need to invest anything as Thailand Corolla has all the stuff like push start, electric seats, projector lamps, smart entry etc.
Rims are sure going to be changed to 16 soon also.