Except that no "bill" can do any such thing. The status quo that's passed today can be quietly amended and reversed as an amendment to some other bill next session.
The author proposes that the biz-owners are rammin this through precisely because the status quo is about to change and, according to the author, they want this passed to protect them from the next Prez and Congress which will sweep away all the pro-amnesty congresscritters.
Thus if the author is correct, and their pro-amnesty protectors are swept out of congress, then the big-biz pro-illegals will be even MORE vulnerable in the next congress because their protectors will be gone, and Hillary is going to find a way to crush their balls no matter what legislation is passed this session.
The supporters of amnesty can be wrong, and also believe that it's the right thing to do at the same time.
The pro-amnesty people may just simply believe that what they are doing is the best compromise they can get before Hillary gets in and they have no say, and that doing nothing is worse.
The author's explanation here for their motivation falls short.
Wrong on one very important point. If this bill passes, the 12 to 20 million illegals with be given legal status. Once that is done, it is game, set, and match. No matter what future Congresses may do, and I believe they will try to remove whatever "concessions" the Dems made to get this bill, e,g., changing chain migration, you can't unring a bell. These 12 to 20 million will be legal residents of the US now and forever more and will be able to bring in their spouses, children, and parents. They will also be entitled to paid legal representation and SS numbers. Once that is done, nothing else really matters in terms of how this will destroy this country as we know it.