A reasonable solution would be to recognize abandonware as a legal category under copyright law. If a company decides to tax write-off a work or let it go out of print (including print on demand for an obscene price) then revoke the copyright and put it in the public domain. Tax write offs that weren't ever released like Warner Bros has become infamous for of late should additionally be required to be publicly released. Uploading it to something like a "Warners Bros Tax Write offs" Youtube channel would be sufficient for preservation purposes.
If you do that, the preservation problem will take care of itself between organizations like The Internet Archive and the various piracy groups. This might also make it easier politically to crack down on the pirates who insist on distributed unauthorized copies of new releases by making them less sympathetic.
It is a little more complicated than you describe because copyright doesn't just apply to published or finished work. That means you are effectively advocating for the end of privacy.
For example, it is pretty common for famous or even some private peoples' diaries or letters to be published. Will you sell me a copy of every single one of your emails? Oh, you refuse to sell them? I guess that means you forfeit your copyright and now anyone can sell them.
The right for a creator to stop the distribution of their own work is pretty important. I agree that we should tweak the tax write-off process to maybe force that work into the public domain, but worked destroyed for tax purposes is only a tiny fraction of all abandonware.
Copyright law already recognizes a concept of "work for hire". Limiting the "abandonware" concept to only works for hire would trivially address your concerns.
It would also open up a trivial hole to exploit this. Lots of creative work, especially written work, is not done as work for hire. That would expand more the more you disincentivize that categorization.
If you forfeit your copyright for the purpose of a tax right off, and to abandon your responsibilities to the work, then your work reverts to the default status (prior to any copyright law) of public domain. (And, Yes, you better make sure you have the rights to public domain every part of the work, or you don't get the right off.)
If you retain ownership rights (+ responsibilities) then you don't get the tax write off.
Or at least send a watermarked copy to the Library of Congress for future preservation. If those copies get out, the US can reimburse them or…something.
If you do that, the preservation problem will take care of itself between organizations like The Internet Archive and the various piracy groups. This might also make it easier politically to crack down on the pirates who insist on distributed unauthorized copies of new releases by making them less sympathetic.