The changes resulted from what would have normally been a routine update. However, the host (IPS) has included major changes in the layout for the new version. I've checked into it and the older version is going out of support shortly. Therefore, switching to the prior format won't be an option. On the upside, the newest version does contain all the latest required security updates. We will be making some minor changes on the site. However, the core functionality will, out of necessity, remain the same. The host is also the company that produces the software used on this board. The advantage being that the board stays up to date on all updates. The disadvantage is also that it stays up to date on all updates.
I'm researching a few of the issues. The reason that your name may have changed is the result of the fact that the board now displays your username for your name. The old version supported something called "display name" which it would substitute for your username if you had display name set. IPS has chosen to eliminate that particular feature.
We will make changes in areas that we have the option to do so. However, in the world of computers, things are always in flux.