Unless Banquet has changed the packaging, the aluminum plates were not included in the original VS4-10 Phoenix Kit (ie. the kit with portal axles. The kit includes the plastic plates, as well as a plastic motor plate, and plastic transmission standoffs. Again, unless Vanquish has changed what's included (since the Phoenix Portal was released), of you want the aluminum versions of these, you'll have to purchase them separately.
Also, be aware that the kit includes sintered metal gears. If you want stronger (ie. CNC machined) gears, those will also have to be purchased separately.
Overall, the Phoenix Portal Kit is a fantastic kit...was VERY enjoyable to build...but, in order to help keep the price down, I can understand why they chose to include these plastic & sintered metal parts. Put another way, this allows them to "make up the loss" when people order the 'upgrade' parts. Other companies do the same thing (heck, Tamiya offers many of their kits in different 'trim' levels, with each 'level' above base including more & more upgrade (called "Hop-Up") parts), releasing a variety of upgrade parts at the same time a kit is released, and then releasing more upgrade parts as time passes - Traxxas does it, Associated does it, all the Horizon Hobby brands do it, Tekno does it, XRAY does it. In other words, they all seem to do it this way.
Whether you stick with all the kit parts, or upgrade all upgradable parts, you're going to luv building the Phoenix Portal.
~ More peace, love, laughter, & kindness would make the world a MUCH better place