We still get a physical tag.
We just don't have to put it on. Nor do we actually have to carry it with us, if we are allowed to use our drivers license or a $3 card we can carry in our wallets. That DNR officers can scan like a credit card to see if we have purchased our license.

We also don't have to go to a physical registration station anymore. Not that there are many of those around anymore either.
Not many places sell licenses anymore either, except Wal-Mart, and a few die hard retailers.

SO yes, more deer MAY go unreported then have in the past. But you're correct, poachers will still poach and those who do it the right way will still do that too.