How lucky! I have yet to get one that suckers, let alone one that would sucker 20 feet away. So I would say, no, it did not sucker or produce offshoots. More likely one of your neighbor or your camellias produced seed that ended up in that spot. fyi - camellia seeds do not usually produce identical plants from the parents.

I just noticed the first bloom -it looks identical to my neighbor's camellias' bloom!

My "volunteer" camellia was hiding in my huge azalea bush (which is almost 4ft tall), so I didn't notice it until the azaleas were dying down for the season.

Oh, wow. Yes, I can see that happening in your zone! Be careful moving it because azaleas have tiny fibruous roots in the topmost 4". It is going to be impossible to transplant it without making the azalea put up a fit.