Yeah, that rear fender looks pretty frumpy. But watch out, it will grow on you. It is perhaps the most authentic piece of the Enfield tradition.
I think that rear fender is also the ugliest part of the bike but taken as a whole it just fits. There is a character to it that just makes it look right. The more I see it in person the more I think it fits. Still not my style though.
I'm sure you could mix and match parts, do some paint and fabrication, and get a nice round fender to fit. If that's what you seek check out the C5, that's the way it's made in the first place.
I don't know for sure but I think this bike will be around for a while. It's basically made from all the older parts (frame, fork, sheet tin) with the new engine, easy to make many, many more. That's why it's inexpensive, all the overhead on the jigs and molds is already paid off and no need to stop the line and change paint colors. My local dealer was curious how they'd sell and I think he's already sold two. I think it combines the best aesthetics of the G5 and C5 into one machine. There's something to that bike.
Scott