Talking of series for which "update" is a relative term, As N Approaches Infinity (the BLEACH/Puella Magi Madoka Magica crossover several worlds need) did not itself update Monday to celebrate its fifth anniversary, as author Corisanna got body-slammed by real life. However, comma, another Significant Figures author, astrologia, marked the date by completely revising the two extant chapters of their possible sequel-fic The Worst Thing Next to Anarchy (Is The Government). Start here; it's not far to go just yet:
https://archiveofourown.org/works/176937...s/41735564
https://archiveofourown.org/works/176937...s/41735564