the tar that is in the op is a full dump of a phones software with all partitions available for use... so it would have the boot partition, system, cache etc... this information is needed to get around the locked bootloader, (namely the boot.img and some other info) and to find an exploit to get root... this information also cant be pulled from the phone without root access...Thats my question, whats the benefit. how can we use it to our benefit if we could get it to work. i wouldnt want to take the risk if the benefits dont outweigh it.
nobody WANTS to root the old leak and have to use it, but better slightly older but working rooted software then current non rooted software... also if they find an exploit that works on the old leak their is a chance that it will work on the current software on the device...
the above is my understanding, i may be a bit (or completely) off as im not a dev, this is from reading through the forums and picking up stuff...