My interpretation of that paper is that it is saying "We don't have hard enough bounds on the parameters of the Drake Equation, so one (or more) of the paramete

My interpretation of that paper is that it is saying "We don't have hard enough bounds on the parameters of the Drake Equation, so one (or more) of the parameters could be much lower than expected". But without specifying which parameters are much lower than expected, the paper is just saying "our current understanding/uncertainty about the universe is consistent with someone solving the drake equation in some unknown way at a later point in the future". Which I don't think is actually a solution. The real question we are interested in is which parameters are lower than expected and why.