i've looked the FCOM for A318 and A320 and it does not have the NOTE that the A319 has.
so the A319 with a MLW of 62.5 tons, AIRBUS SAYS, that the crew may perform an autoland up to 69 tons. Why would they say 69 tons ? i'd say they've probably tested it, and that's why they say UP TO 69 tons.
A318 and A320 do not have that note. Do not know about the A321