There is no such thing as a DST time zone. And it makes no sense to say 'CC is on DST 24/7/365'.
During the winter months, the Eastern time zone uses Eastern Standard Time (EST, UTC-5 hours). During the summer time the Eastern time zone uses Eastern Daylight Time (EDT, UTC-4 hours).
The CC servers should not be said to use either EST or EDT. Instead, they use a constant UTC-5 hours. This just happens to coincide with EST. It also happens to coincide with Central Daylight Time (CDT) which is why those in the Central time zone now match CC server time.
As for which way to do it - I live in the Eastern time zone, so obviously I would prefer the servers switch to UTC-4 hours. But keeping the same time offset is fine. What guilds need to do (if they want to) is shift when they do events by 1 hour (server time). Unfortunately this isn't an option for things like TB and FF. But it is fine for bosses, lava, etc.