You may want to argue that IP is also part of these deals and past employees created part of that. This is probably true for some deals, but it has been minimally true for the deals I've seen directly. Sample size of two isn't great, but keep in mind the value of startups is largely believed to be in execution, not ideas. A startup on the verge of bankruptcy probably doesn't have immensely valuable IP because it's 1) not producing present value obviously and 2) isn't obviously worth a lot in the future, otherwise someone would be willing to give you discounted cash today for an ownership percentage of its future value (aka an investment).
Out of curiosity, how do you keep the employees from walking after an asset only transfer? The vague promise to them about future riches has already been broken. And you will up changing business practices that ruffle feathers (I'm not sure how you could avoid it. This stuff is rarely written down). Hell, you'll probably assign them to a new project anyway. So how do you keep them from leaving in droves?
And you didn't ask, but if not enough of the team accepts an offer, then it evaporates.
Effectively, he had no job but was still on the payroll for a year and maintained his equity. He came in and did virtually nothing for about 6 months and then stopped.
It's a cushy gig but by the time you get it it's a punishment not a reward.
Their compensation at the new company will have a vesting schedule over some period of time, similar to a stock grant.