There are three categories of individuals that cannot be communicated with on Remind: teachers who have disabled 2-way reply settings, students under age 13, or individuals without a completed Remind account. All of the folks that you see listed as "Pending", aside from yourself, fall into one of those categories of users.
On our last update of the app, a change was mistakenly put in that added the "Pending" title alongside one more category - individuals own names.
This is giving you the illusion that you can't be communicated with. The truth is, you just can't communicate with yourself. Everyone else can communicate with you.
Any other participant who logs in and views the People list for the class from their app will see that they can send you a message.
The "Pending" only shows in your view, when you're logged in as yourself, because you can't message yourself.