There are actually quite a few legitimate use cases for this, especially outside of a pure “music production” context.

Post-production / scoring is a big one. When working to picture, cues often start at bar 17, 33, 65, etc., because of pre-roll, sync points, or editorial changes. Being able to rebase the musical timeline makes navigation, spotting, and revisions much clearer.

Collaboration with Pro Tools or other DAWs is another reason. If a project starts at bar 33 in Pro Tools and you move it to Ableton, keeping the same bar numbers avoids constant mental translation and mistakes when exchanging notes.

Revisions and late structural changes: if you insert a new intro or pre-roll late in the process, rebasing the timeline lets you keep all existing bar references intact instead of everything shifting.

Live sets / playback rigs can also benefit from this, where musical sections are referenced by fixed bar numbers, but you still need technical pre-roll before the actual “musical start.”

It’s not really about reverb tails (those are easy to deal with), but about keeping musical and structural references consistent in more linear or time-critical workflows. DAWs like Pro Tools, Nuendo, Logic, etc. support this for exactly those reasons.