I see this claim all the time and it's obvious bunk. The filibuster was first used (that we're historically aware of) by Cato the Younger in the first century BC and used many times after in the Roman senate. Given their huge fetish for all things Roman even to the styling of federal buildings (and styling the US senate after the Roman senate), I fail to believe that the Founding Fathers, such as Aaron Burr who put the rule allowing for the filibuster in place, had no idea how that would work.
I don't claim that a concept similar to the filibuster did not exist prior to that time. They didn't copy
everything the Romans did. The business of Congress is very well documented AFAIK so there should be ample documentation of whether the people at the time expressed an opinion/intention about the rule change (and it was a rule
change) leading to something we would recognize as a filibuster. I admit I haven't read it personally but I have been told their expressed intentions point pretty clearly to other reasons and expectations. I don't really recall my source, much less put it on a pedestal, so I'm open to being told I was lied to if there's a good source for the contrary position. Have you any less speculative information that would point to that reason or expectation?
And there is also the Federalist 22 argument against what filibusters allow.