Esri's use of "deprecate" is consistent with the rest of the software industry. They try to be
as explicit as possible (hence the update to include the 10.2.2 service pack), but predicting
the future is notoriously hard, especially 2-3 years out, when most deprecation notices
are produced.
I disagree with your assertion that it would be possible to deprecate something at the version
in which it was removed. Deprecation is always a future-looking process, which says, in effect,
"You can still use it now, but get used to the idea (now!) that you won't be able to use this
feature in the future." Imagine if aircraft manufacturers deprecated landing gear in an
announcement that caused the wheel axles to disintegrate.
There is no hard-and-fast "n vs n+1" rule in the deprecation market, yet it is the minimum
effective notice that can be given, and once the decision is made, the developers have to
start working toward that goal. It isn't always possible (Oracle deprecated use of LONG RAW
back at 10gR1, and it was still available at 11gR2), but it is good practice to make the change
as soon as practical (to avoid the "Well, we'll keep using it, and maybe they'll not make the
change, like last time" trap). I do know that Esri is working to augment ArcObjects, Desktop,
and ArcPy to eliminate the need for ArcSDE command-line tools, so it seems very likely that
the "n+1" goal will be met.
- V