I'm happy to see the site with new features and functions, but it would be better to bring the old data as someone already took my username, I used to bet. I wonder what made the site owner think about switching the website while the old one was running well. Not only this, the site owner lost the data too. I know we have more features in new sites, but the site owner should take care of their clients' data or lose trust.
The platform looks much better and has a lot more improvements. I think the changes were thought out and everything was done in the best possible way. It is possible that in terms of the usernames base this may simply not be technically possible. The most important is that no one has lost money.