I noticed that the campaign guides use two different bullet icons in their bulleted lists. One is a diamond/lozenge/rhombus and the other is a right-pointing triangle.

Are each of those shapes intended to denote different things?

I think it's about one being permanent effect and the other an one-use (like free deployments). Like the choices in aftermath.

See the second page of the (core) campaign guide.

◆ is a persistent mission rule, ►is instantaneous mission rule.

Ah. I was looking in the Rules Reference for that. Thanks.

There are only a few things that are only in the LtP or campaign guide, this is one of them. (The other that I remember off the top of my head that you can also reinforce during any optional deployment.)

There's nothing secret before page 4, so it's also highly recommended to go over that second page with the rebel players.