Hi scoaste,
This isn’t correct. If you are a member here and post on the forum and you order through the Dreamfoam site (not Amazon) then they still offer a pillow bonus and all you need to do is let them know you are a TMU member either in the order comments or through an email.
Most foam mattresses don’t have or even really need side support if they have a support core that is firm enough and the comfort layers aren’t too thick and/or soft for the person sleeping on it. Having said that … there are exceptions to every rule and there is more information about edge support and foam mattresses in post #3 here and in post #33 here. With a foam mattress that is a suitable firmness level relative to the person sleeping on it (both in the support core and the comfort layers) then it normally wouldn’t be a significant issue for most people unless you often sleep or sit with most of your weight concentrated on the very outside edge of the mattress although the outside edges of a foam mattress would generally be softer than an innerspring mattress that has a specific edge support system.
As they mentioned … latex in general is a more “supportive” material than memory foam. There is more about some of the more general differences between latex and memory foam in post #2 here.
Phoenix