blank deed of trust in RE loan files

Our RE manager tells us that it is standard practice to leave a blank deed of trust in loan files "just in case" the loan later is sold on the secondary market. We told her we consider this a risk as leaving any blank form in a loan file is a risk. I wanted to check and see if leaving a blank deed of trust in an RE loan file is standard procedure at other credit unions (I've personally never heard of this). Thanks!