A 200m velodrome is fine for international competition. The UCI Center in Switzerland is 200m and has hosted international level events. The difference in riding a 200m vs 250m is much smaller than 250 vs 333, or even between 166 vs 200. For a grassroots track that is most likely going to be crowdfunded, then 200m is ideal. Barring Madisons and Points Races, it's also easier and more inviting for spectators to watch on a smaller track.