You can work it out from the bottle. For example, for the Egly-Ouriet Extra-Brut V.P. on my desk, it says on the back label that it was disgorged in July 2019 (Egly disgorge all their releases for the year at the same time, July, every year), and that it spend 84 months on the lees. So you can see that the wine was bottled in 2012; which means that is it based on the 2011 vintage. Reserve wines will be from 2010 and 2009 (the Extra-Brut V.P. and the Brut Grand Cru are always a blend of three consecutive vintages).
The DD is valuable to know how long the Champ. did develope in the bottle off its lees … 2013 DD seems quite young to me, except you like it only fresh without any bottle age. I have dozens of Champ. from the 80ies and 90ies drinking fine (for me), I like the taste of brioche and bread crumbles in aged Champagne.
DD is useful to know the used vintages only if you know the house style anf practice.
When I buy NV champagne at auction, it’s always a crap shoot on the disgorgement date. I would like to know so I can estimate the evolution of the wine in the bottle. But sometimes it’s great not knowing because it becomes a surprise when you finally find out.
A recent example was some bottles of Mumm Corton Rouge that I bought through Winebid. After receiving the bottles, I was able to decipher the code on the bottles to determine that these had been disgorged in September 1997. To me, and my appreciation of ageing NV champagne, that was a fabulous surprise! The wine in the bottle is much more complex that new Corton Rouge, further proving that NV champagnes can age very well.
I like the way you describe the “rolling the dice” aspect of a possibly old NV. That is life in a nutshell isn’t it; wonderful surprises await, but it still stinks when you crap out.
I think this is even more important than knowing which release and base vintage(s) you have (although I like to know that too, especially with wines like Pierre Peters NV where some releases are so much better than others). Personally, I would definitely not buy anything disgorged more than 2-3 years ago. I have opened many such bottles that have been in some combination of wholesale warehouse and/or retail shelf for most of that time, and well over half have not been in good condition.
It’s worth adding here too that on some producers there is a disgorge date etched into the glass on the bottle (Marie Courtin comes to mind for sure and either Jacquesson or Larmandier-Bernier–I can’t recall, in part because I am 54 and have CRS). It’s cut right into the glass and will give you a disgorge date indication. Sure, not everyone does this and it’s not a industry standard but there is sometimes info lurking on the bottle and it can be decoded, in some instances easily enough.
FYI. I have a half bottle of Roederer Brut Premier on deck and was poking around to see if I could figure out the date of disgorgement. That info and more is available on the Roederer site. Just plug in the code on the back of the bottle and voila! FWIW.
The colored bottle actually works to your benefit by negating the effects of light strike on the wine, Lanson screams out for a bit of bottle age to drink well anyway.
You might be surprised at how much you enjoy it.