Does the following mean that users with Weaver Xtreme 5.0.2 no longer needs the Weaver Xtreme Support plugin?
V5.0 had code that depended on the Weaver Xtreme Support plugin to create and write some style files. Sites without the Theme Support plugin failed to have any styling display. But because V5 does not overwrite any V5 settings or files, it turns out that no data was ever lost. It just takes reverting to V4.4, which thanks to the somewhat new process WordPress follows when uploading themes, it is pretty simple to do that. This problem has been fixed in V5.0.1.
Personally, especially since the addition of the Block Editor, I find the most useful thing in the theme support plugin is the Legacy Interface. But even that is less so since the addition of the Where customizer interface version.
Most of the shortcodes are fairly obsolete. The [extra_menu] and [showhide] shortcodes remain useful for somewhat specialized uses.
There are also some extras for managing settings backups, but Weaver Xtreme 5 has added more options to Save/Restore, so even that functionality is not really essential.
So the Theme Support is not absolutely essential, but is also does not consume any resources until opened or ever cause any site speed issues.