Its not about being special. This happens to be one of the things that fall in the competency of the local bishop or Episcopal Conference. So they can make a decision on it. In the US they decided to abrogate it. In other Episcopal Conferences in other parts of the world, they may have done the same, others may have kept the Obligation.
I can understand moving other holidays because those days being work days, it may be harder for people who work to go to church. But days of obligation on non-working days such as Jan 1st shouldn’t have the same issue. I guess US bishops are just avoiding confusion on 2-fers, or perhaps by past experience they found out that it wasn’t well attended anyway.