Our new 2014 Trail (NOT the premium) came with the plain-Jane manual-dimming mirror, and no Homelink buttons at all. Likely due to cost-cutting, and to get buyers of the Trail Premium to believe they are getting more bang for their bucks besides sticky seats in the summer.
So for us, YES! We get an auto-dimming mirror AND Homelink buttons. I got the mirror off eBay for $75, as it was a take-off from a Subaru where the owner wanted an On-Star mirror instead. these mirrors are $250 if bought new from Gentex/Milo. New ones on eBay are $209.
The cable I ordered to connect-up the mirror should arrive tomorrow or Friday. I removed the o/h console this morning and believe I found a good spot to splice in the three wires for the mirror. I will verify with my multi-meter when I'm ready to splice, but the wires are in the big white connector that plugs into the o/h console.
Some Toyota models (Camry, Tundra, etc.) apparently have a 3-wire connector as part of the o/h wiring harness that you can just plug or splice into, but 4Runner owners are not so lucky. I may do a DIY thread with photos for others who want to add the same or similar mirror.