Film conversion is also referred to sometimes as film confectioning (in the UK primarily I think).
That process encompasses all the steps between the coated master rolls - which are very long and wide - to the final stage where the finished packages ready for retail sale go out the door.
Those steps include slitting to the necessary width, perforating (where required), edge printing(for roll film) or notching (for sheet film), cutting to the required length, including any film tongue, spooling on to individual spools (for roll film), cassetting (for 35mm) or marrying with backing paper (for 120), bagging (for sheet or bulk loads), boxing and probably a couple I've missed.
If those processes can be automated, than costs per roll can be minimized, which helps keep prices reasonable. Where those processes have to be performed with a lot of manual labour, such as with sheet film or, at least in Kodak's case, bulk loads, the costs per sheet or roll end up being relatively high.
The remaining coating machines have high throughput capacities - even after they were reduced after the near collapse of the film market. As the market has creeped back, the conversion/confectioning has become a bottleneck. There also is a relative shortage of sources for 35mm cassettes.
Harman is apparently already providing contract converting/convectioning for other film sources. This will expand their ability to make money on that.
And I'm sure that "cassettes" refers to 35mm cassettes.