I think if regular meeting attendance wasn't a requirement most people would still go. Only the people who really did not want to be at the meetings, in the first place, will use it as an excuse not to go.
Most people would see it as a sign that the Great Tribulation is about to errupt.
They would say, "See, Jehovah is preparing us for the Great T when the meetings will have to go underground. Jehovah wants to test us to see how we will respond during the Great T!"
Plus, you will still have those competitive people (pioneers, elders, and elderettes) who would say, "Even though regular meeting attendance is not mandatory, I do not forsake meeting attendance because I love Jehovah."