Oh I absolutely love this guy, the moa! When I first started out on Ark I was so fascinated by the terror birds, the flightless bipedal murder birdies, but I've always been a little disappointed that there wasn't a whole lot that you could do with them.
The moa on the other hand would be fantastic! A non-conventional taming experience, functionality, and unique appearance which ultimately doesn't make it ridiculously overpowered or ambitious. Not to mention he would fit perfectly in Scorched Earth, providing a fun means of transportation through the map. Love it. Great suggestion. Will definitely be voting for this guy.
Good luck, mate
Edit: In response to those saying it is useless, I disagree. I play on Official PVE and Solo and yet I can easily see myself using the moa plenty. The platform saddle may only fit a bed and/or smithy, but with its speed and AOE attacks it will make for a wonderful tame whenever you need a convenient transport for excursions: Drop collecting, land surveying/exploring, egg carrying for when breeding or snagging eggs on the fly, etc. I think it'll be a fun addition overall, for new or old players.