Of course I agree that it would be much better to include true value-added bonus features such as commentaries by Peter Falk, Bill Link, Stephen Spielberg, etc.
But, since Universal instead made the decision to include "Mrs Columbo" as the bonus, I hope they will follow through and include the fifth and final "Mrs C" in the upcoming DVD set for seasons 6/7. (Maybe I'm mistaken, but I think they have given us 4 of them, so far.)
This way, loyal fans and purchasers will get the full series for both shows (pending, of course, a decision as to the ABC "Columbo" episodes).
Bear in mind that there were only 5 true "Mrs Columbo" episodes, before the Mulgrew series changed concepts, names, etc.