There is nothing official about the 1800MHz LTE band. Most "sos kicap" mentioned are blog posts which I wouldn't put too much stock on those things.

MCMC only licensed the LTE Band #7 for LTE and the License was awarded to 8 players. To be able to open up the 1800 MHz frequency, they will need to do another round of bidding, by then the iPhone 5 would be superceded by the iPhone 7 or something like that.