Phase II: Migrate Archive says "Set MediaWiki to not remove rows from the text table when deleting revisions", but MediaWiki only ever did that between r7318 (30 Jan 2005) and r8772 (1 May 2005). The ar_text and ar_flags fields have been unused except for legacy rows since r8772. The sub-bullets there don't make sense either.
And unless you're adding logic to MediaWiki to copy data out of the content table back into the text table on undeletion, this Phase II would totally break undeletion.
What really needs to happen is one of the following:
- Migrate rows that have non-null ar_text and ar_flags into the text table, blanking those fields and filling in ar_text_id in the process. Then populateContentTable.php would have to handle both the revision and text tables.
- When populateContentTable.php processes the archive table, have it go from ar_text_id+ar_flags→content in one step. I'd recommend this, and it eliminates Phase II entirely.