As plenty of others have said - nope, dissaving is very uncommon word. As a native American English speaker, I don't recall ever seeing it either.
One clue for future reference - the linked article had to clarify the meaning of the word _in the title_. That strongly indicates to me that, even if in certain areas the word is well understood, the author expected there to be confusion.
One clue for future reference - the linked article had to clarify the meaning of the word _in the title_. That strongly indicates to me that, even if in certain areas the word is well understood, the author expected there to be confusion.