Sounds very fishy, I'm assuming they think you have the old needle bearing which was superseded in around early 06.
But if they do, then why aren't they saying replace the bearing too. The bits they've named are the pressure plate, lifter piece/pullrod, washer only. And you don't need that washer with the new versions of the other 3 parts.... also, replace them with steel? The lifter and the washer are already steel.
This guy sounds like he hasn't got a scooby doo.
In your 2015 engine you have all the latest clutch bits, and imo updating fibers, springs and outer basket do not require changing those bits your Triumph guy listed.
From another thread;
For engines older than #249177 (04-06 silver engines primarily), i.e. with the needle roller thrust bearing T1170029, you should get these parts also;
- 1no. New clutch lifter piece T1172023
- 1no. New lifter shaft T1170041
- 1no. camchain tensioning guide T1142048
- 1no. Pressure plate ball bearing T1170067
- 1no. Pressure plate T1170061
- 1no. Wavy washer T3550380