I would imagine half of Pennsylvania didnt renew their registration due to this change. Give people an inch....
As the legislator/retired trooper stated, they just need an extra visual aid for an excuse to pull you over to find some violation which might bring in more revenue to the state.
Of course, he didn't use those words, but that is what he means.
FWIW, I do drive out of state from time to time. Maryland, Ohio and West Virginia are all within an hour. An old sticker on a PA license (even though no longer required) is a cop magnet. So I solved that problem by getting a new plate from a fraternal organization to which I belong with whom PennDOT has an agreement-- the state gets a cut of the donation. No old stickers = no cop magnet. Well worth the price.