Hummm...Lets see, Rossi, Charter Arms, and Taurus dropped this caliber from their lineup recently. That should be an indicator of its popularity.
Rossi hasn't offered a model chambered in .327 Federal. They can't drop what they don't make.
Taurus didn't drop it. They changed models, barrel lengths, and made the current model a limited-production affair.
It's true that you can't find a Model 327 in their catalog this year, but... the 327 has never been a cataloged item. It was always an non-catalog item.
Dig around online, particularly on auction sites, and you'll see the current 3" bbl model quite frequently.
And... Taurus dropping something is no real indicator of popularity of the cartridge or platform. It's an indicator of popularity for THEIR product. Talk to dealers that sold Taurus revolvers during the '90s, and ask them about the .38 Special revolvers that disappeared for nearly 2 years. It wasn't because no one wanted the
cartridge. It was because no one wanted the stupid variants
Taurus was producing.
Charter, as it turned out, made the same mistake as Taurus: They neutered the platform, by cutting the barrel too short. It got poor reviews, and suffered because of that short barrel.
But... what you didn't cover in your post, is that S&W is still producing .327 Federal revolvers, and even ADDED a model this year. We also have Ruger, still offering three models.
.327 Federal is not just holding its own, but still growing.
For further reading, we have this monster thread going:
29 pages of terror