That's an easy answer. Mac Baren was up for sale at an attractive price, so you buy the company, own the catalog of blends, bring in any specialized equipment that you can use, scrap the rest, and sell the property for a profit. Sutliff is collateral damage. STG already owns Lane, which was an operation similar to Sutliff, so no need for two of them, and you still own the catalog which you can use.
It's not like there's anything new about this. K, formerly K&K, bought McConnell in the 1980's, and have added a number of catalogs to their holdings, like Rattray's. Most blends are made by only a few companies who own a pile of IPs. Gallaher bought Cope's way back in 1952.
Dunhill stopped making their own tobacco products around 1981 and licensed Murray's and McConnell to make their blends. Dunhill never made Navy Rolls. That was a Murray's creation.
Savinelli didn't make their blends, Mac Baren did.
The era of dozens of manufacturers making a limited array of blends is long, long gone. It's now just a handful of manufacturers, some of whom own many brand names.
The majority of pipe smokers have no clue what it was like, the level of individuality, and never will. We've been in a consolidation mode for decades.
When you look at a page on an online site with dozens of different brands displayed, it's an illusion.