I feel like a lot of people are completely unaware that Tom already tried to surprise Jon at a meet and greet a year ago. Jon laughed it off and shook hands and hugged him just fine. Then Tom slapped his hand on Jones shoulder like a "father son chat" pose. Jon immediately slapped his hand off and shook his head at Tom to knock it off and Tom apologized. Jon's smile never wavered for a moment despite this.
The Jon in people's heads is not the real Jon. Even just from watching his career you should know he's prepared to do something spectacular and overwhelming from out of nowhere. It's what he's known for. Why would you ever think he wouldn't do the same outside the octagon lol.
While again, having already done so against someone like DC.