Not everything is a vague or esoteric reference or piece of
symbolism though. Sometimes things are meant to just be taken at face
value. When we look at things for symbolic context, we run the risk of
shaping the symbolism to support preconceived notions or theories
without actually taking the context into consideration.
On a local, recent level. When LeArk pointed out the symbolism of
Johan's ace monster name in the manga, Danus, he referenced the Greek
mythological figure. But then Lil_Yugi pointed out that it could
probably reference the butterfly genus of the same name. So....it all
depends on context and intent.
Would the creators really go through this much trouble and opaqueness to
give us the year of 5Ds, when before they had no trouble at all telling
us the year and era of the previous YGO series? It just doesn't seem to
match up with past behavior or logic.
I'm honestly thinking they're maybe saving the actual year of 5Ds for
when its over as a big reveal or something. It seems like they're being
purposefully vague about its era for a reason.