It is not a warranty seal or a safety seal, it is a tamper indicating seal.
If the sticker was for safety, it would indicate not to do something in bright colors with internationally recognized cautionary symbols. I think it is pretty obvious that the sticker is a proprietary tamper sticker, not a generic safety label.
Whether cutting it voids the warranty or not is up for debate. They put it there for a reason, but I imagine it just serves to indicate if closer inspection is required prior to their usual troubleshooting. Looking inside your radio should not void the warranty. Imagine auto manufacturers taping hoods shut lol.
This forum is all about tearing into radios, I don't think anyone is framing their warranty cards here. If you value your warranty, ask them to fix whatever problem that has you ready to cut the tamper seal.