Baltimore Maven:
This quote from Rav Weinberg ZT”L is not his own line. It is quoted from Reb Naftoli of Ropschitz. He was known to say quite interesting and sharp witticisms. The reasoning he shared for this was that the בן רשע of last year has now become the בן חכם, so a new haggadah is needed. If you can relate to the concept of התקטנות הדורות, this should make sense to you.
Assuming that one covers the entire peirush in this year’s haggadah, one should need a new one next year to add to the database of pirushim. This also assumes near perfect memory.