Smart move by the NHL / NHLPA (assume they would have got PA approval)
Look at the discussion the expansion draft has generated so far. When those lists come out, it is going to give the NHL a whole bunch of media attention and fan discussion in their off season.
I know the NHL doesn't officially support / supply the salaries, but look at the discussion and media attention the cap and salary websites have generated for the NHL. Expansion draft is similar, players probably won't be thrilled about it, but it is great for marketing and drumming up interest.