Based on the Tautulli sub-reddit…
“Assuming that Trakt has an API you can report plays through, you could write a script that queries the Tautulli API and sends that on to Trakt.”
And considering that trakt DOES have an API, specifically for syncing…
https://trakt.docs.apiary.io/#reference/sync
"As a baseline, all add and remove sync methods accept arrays of movies , shows , and episodes . Each of these top level array elements should themselves be an array of standard movie , show , or episode objects.
It seems that ‘someone’ would just have to write the Tautulli script and off we go…