Other than the use of cte, I don't see any fundamental difference between your code and what I posted earlier, although I admit I haven't thoroughly reviewed it, since I'm...

Does YYYY-MM-00 -- not to mention YYYY-00-00 -- raise 1NF / atomicity issues?  Does the column represent an atomic date or a range of dates?  Is the range somehow deemed...

My (strong) preference is instead to use EXECUTE AS on the CREATE TRIGGER:

ALTER TRIGGER [SchemaChange_LogInTable_DDL]
ON ALL SERVER 
WITH EXECUTE AS 'big_cheese_login'
FOR ...
...

I think you can use NOT:

IF NOT UPDATE(col19) AND NOT UPDATE(col20)