The 325WSM as well as several cartridges, have been introduced mearly to increase new rifle sales.

It is the age old new marketering trick. That is why cars have to look different every year, and radically different every few years...

However just looking at its ballistics, I feel it would be an excellent medium bore cartridge.

There in lies the problem... GOOD medium cartridges have traditionaly not done well over a period of time.

IMHO medium bore cartridges are some of the best hunting calibers for the North American hunter.
[Africa as well].

Rounds like the 325 WSM, 358 Win, 350 Rem Mag [owned one, liked it], 35 Whelen, 338-06, 9,3x57, 9,3x62, 9,3x74R,[use one now, it is a great hunting round] and the great old ones like the 318 Westley Richards, 333 Jeffery, 400/350, etc. are great killers.

With good bullets they will get the job done, and done very well.