I too can verify on the 2014 - 2017 4Runners that all you need is a newer map update microSD card. I bought one off eBay, 2017 update, 86271-OE184. I have the Entune with the hard drive. When I put the OE184 microSSD in, and turned the key to ACC, I was prompted with:
"New software found"
"New software is ready for update. Park your car in a safe location, and turn the engine off and on to complete the update, INSTALL"
"Installing the new software... Please keep the media inserted and do not turn off the engine"
"Software update has been finished successfully to version v0101D4, RESTART"
Process took 9 minutes.
Before: Map version 05-33-08 2013-06-8 (86271-35010)
After: Map Version: 05-36-51 2016-05-1 (86271-OE184)
I read here that Toyota map updates are released in the fall. Toyota drops the price in the spring. I think Toyota dealership quoted me (Spring price) $149 plus labor. Buyer beware on eBay because people are selling old microSD map updates. I was going to upgrade the head unit if I could not get a fair price on the map update microSSD. Dash comes apart pretty easily. I took the dash apart to clean the multi-information center display because previous owner got something on the inside display lens.