There are annuities that are DB focused.
If the whole life they have now has $80k cv, and the DB is only $100k... my guess is that isn't a par wl policy - unfortunately. If it was the pua div option would have pushed the DB way beyond the $100k mark - assuming it started as $100k policy. Or maybe they didn't elect pua div.
You need to make sure you get an inforce illustration so you know exactly what they have and where they stand.
, replacing a WL that is old with lots of CV is almost always a bad decision - but in certain circumstances it might be fine.
More info is needed to be able to give good advice... for instance how old is the client? How is their health? How old is the WL policy? What carrier and product? And much more.