And your ability to jump to conclusions is astounding but your ability to be an ass is made ineffective by your lack of understanding. Yes, it's completely safe to update but if rely on the jailbreak for your unlock you will lose it. It's completely safe to update because you can always downgrade if you have your SHSH hashed if not you lose that.
The OP astounding lack of necessary information makes for too many assumptions which leads to many possible correct answers. If you ask me if it safe to jump in a pool I'm going to assume you know how to swim, so it's not really my fault if your drown..