Normally, this service should be a godsend for regular phone users that do not plan on rooting their devices, ever. But what about the people that do plan on doing that? For the people who are currently using older firmware with the old non-secured bootloader are safe and can even flash the latest firmware without the new secured bootloader by simply deleting those files from the firmware package. This method is actually proven to work on the Galaxy S4 mini and some people claim that it is also working for the Galaxy S4. Still, follow the steps in that post with caution!
The bad news is that some of the recently released devices on the markets have the new KNOX secured bootloader pre-installed and that could be a huge problem for the users as if you try to flash an older firmware that does not have the new secured bootloader, you will flag your KNOX warranty to 0x1 and same goes for rooting.
It's basically like this:If you flash a new firmware that includes the KNOX-enabled system you will be stuck with it. If you try to flash an older firmware version that does not include it, you then flag your KNOX warranty to 0x1. The huge problem here is that your device gets a special lock in which you will not be able to update to any KNOX-enabled firmware, not even with Odin. This is what happens according to a person named Jeffery Butler who shared this information in Chainfire's post:
FYI...Samsung told me that Knox warranty becomes 0x1(void) when the device with secured bootloader attempts to have non-secured bootloader. MH1 is the very first binary with secured bootloader. If MH1 is attempted to be downgraded to lower version(i.e. MGD) which has non-secured bootloader, then Knox warranty becomes void forever, and this means that the device can be used only for non-Knox device(no container can be created).
According to Chainfire, who is a top developer at the xda-developers forums has said that there is an eFuse evolved in this, which is a technology that allows reprogramming a read-only memory chip in real-time and can generally not be modified after manufacture. From his Google+ profile:
If you have an I9505 you've probably noticed the new Knox Warranty status in the bootloader, and I know some of you are hoping Triangle Away will reset that.Before the new KNOX system came out, Samsung was using a simple custom binary counter which could be seen in Download mode and that was easily reversable back to 0 by using Chainfire's Triangle Away but in this case, the app comes of no help in resetting the KNOX flag.
Unfortunately, that's unlikely. I've taken a look around, I've disassembled the bootloader, etc, and it looks like an efuse might be involved ( == not resetable ). I'm not exactly sure what triggers it yet either.
Mind you, I'm not a bootloader expert nor have I spent hours and hours digging through it, so there's a chance this information might turn out to be wrong later - but that's what it currently looks like to me.
According to some people, while flashing custom kernels or attempting to root the Galaxy Note 3, it constitutes hardware damage on the phone. So be very careful how you play with your Samsung device. It is highly advisable that you research on things before planning on doing procedures such as this.
Sources: XDA thread | Chainfire's Google+