Yes depending on the codecs. Some codecs will and some wont. Also keep in mind bottlenecks with the system will also change this. In other words if you don't configure the system with enough ram that will effect the threading. As will the video card and drives.
Here are the top three PPBM8 scoring for exporting the CPU intensive MPEG2-DVD timeline.
My heavily overclocked (4.5 GHz) i7-5960X with 8-cores scores at about 279 seconds, this is typical of other i7-5960X based systems which we have 6 other submitted scores ranging from 260 to 286
Eric at ADK supplied the first and third results showing a significant Premiere improvement in this CPU only export when going from 14 cores to 28 cores. I hope I got the clock speed correctly, Speccy does not always give the correct clock speeds of the processor unless you run it while the benchmark is running. Maybe he can comment
Jim Short has the second lowest time with his 16 total cores
This export is AVCHD to DVD export. The H.264 timeline that we have in PPBM8 that includes some 4K media does not show such a large variation versus cores, but this may be due to the fact that that export is GPU assisted.