Simon,
Yes, if they were trying to save costs back then, they would have dropped the "duplicate" 501 CM back then too.
And a number of other cameras too.
The 501 C and CM were part of the second tier, entry level Hasselblad. And part of the "stretched out" life of the good ol' 500 C and C/M. The one continued when the 503 CX came out as (and because it was a) Classic.
Times are bad now. So it's probably not a good idea to carry a wide choice of cameras (= multiple production lines) when sales figures are bad.
So now it's back to where they once were: only one (1) camera of each "type", but that single camera being the best they can make. No second tier, second choice bodies.
However, the 200-series (too expensive!!!) was dropped completely. No single representative (an affordable 204 FE, combining the features of 203 and 205), no best-of-its-type.
Economic pressure not even allowing that.
Which, by the way, brings the EL-line close to extinction too. What can they do a 503 CW can't?
So expect the EL-line to disappear soon as well.
That leaves the 503 CW and the SWC.
The SWC is (or so i gather) not selling very well. So that may leave...
P.S.
Don't expect Hasselblad's site to announce the discontinuation of any product.
It's there to sell existing products, and (!) those discontinued products there still are heaps of unsold stock of.
You'll know from that site the 501 CM is gone, and sold out, the moment it isn't mentioned anymore.