AWT is not "replaced" by LWJGL 3 or GLFW.
AWT is a window toolkit, like SWT for Java or Qt for native programming, which allows you to interface with the window manager of the operating system and allows you to build windowed applications with widgets (you know, buttons and sliders and tables and all sorts of GUI components).
It's just that with LWJGL 3 you don't need AWT anymore to create a simple render window.