Because they re-released the 321, which is even closer to original.
At least this is my theory, this is part of a bigger plan: right now there is the so-called "original" 1861 (which sells well, but is probably not expensive enough for Omega and the whole "original" thing means they cannot modernize it because people would cry wolf, so they are kinda stuck against competitors), then the '57 range which is kind of heritage but is actually complete non-sense and does not sell well because people attracted by heritage would actually buy a 1861 hesalite instead of this, then the 44.25 range for the larger/techy models in ceramic which is kind of the R&D range.
My 2 cents of what I feel is going to happen:
- 1861 goes away. New 3861 speedy is priced similar to all other co-axial models. This gives Omega a new "modern" watch and is the corner stone of the range. They will have the freedom to make it evolve within reasonable limits.
- '57 range goes away
- FOIS goes away
- "heritage" model is the new 321
- 44.25mm models stay
So in the end, you will either buy a 3861 speedy, or be tempted by the 321 is you really want "heritage" calibre. And if you want something bigger and more techy, you will get a DSOTM. Plus a few limited editions of course, all with 3861.