How long a notice period is long enough?
Looking at it another way, Google's most recent net profit is $18.94 billion per quarter.
I have no idea but if there are 1 million G Suite Legacy accounts out there at $60 per year. That would increase their revenue $60 million per year.
So just assume all that revenue is net profit which would make their quarterly net profit go from $18.94 billion to $18.955 billion for the low cost of pissing off 1 million people.