Merge Train text helper is misleading for Merge Immediately case

We always show the This merge request will start a merge train... text when the MR's latest pipeline is running. However, this text isn't accurate if the user opens the dropdown and clicks Merge immediately - in this case, no merge train will be created.

The text should be updated to display:

This merge request will start a merge train when pipeline # 123 succeeds if you select "Start merge train when pipeline succeeds". More information

Follow-up from "Add merge train helper text to merge request widget"

The following discussion from !14097 (merged) should be addressed:

  • @dosuken123 started a discussion: (+1 comment)

    Please create a UX debt issue that this text is misleading when users perform "Merge Immediately" (for emergency).

    Currently, we show

    screenshot_10

    however, this is not the case when they chose "Merge Immediately". This merge request won't go through Merge Train (and later it's reconstructed) screenshot_9

    /cc @rverissimo

Edited by Rayana Verissimo