Special:LintErrors on kowiki, mznwiki, warwiki show that the lint errors in high priority categories are all fairly small relative to the size of the wikis.
Special:LintErrors on nlwiki shows that there are zero to very few lint errors in the Main namespace for all high priority categories.
Special:LintErrors on cebwiki shows a large number of errors in the deletable-table-tag category, but User:Lsj has been running a bot to fix them all and thinks it is okay to make the switch now.
I plan to make the switch on March 14, 2018 in the 10-11 am PDT morning swat slot.