I agree, a standalone test file is the right call here.
I looked at the same candidates. 025_stuck_on_old_timeline.pl is the closest thematic match, but its archive command intentionally copies only history files and the whole test revolves around promotion and timeline following. Adapting it would mean replacing the archive command and skipping the promotion, which defeats its original purpose.
The reconnect-after-archive-fallback scenario is distinct enough to justify its own file, and at 143 lines it's reasonably small.
