Comics Should Be Goods Comic Legends Revealed had a question about Days of Future Past. The old ending switcheroo. And in the comments a poster said you pulled a switch in the Phoenix story line by having Jean kill an inhabited world when the script called for an uninhabited one. Causing Shooter to decalre "Jean Grey must die!!!!".

My recollection is that the only change you made was to make the planet the home of the Asparagus People rather than Planet Unknown.

To begin with, there was no "script" at that point in the process. Chris
and I did UNCANNY X-MEN "Marvel Style", meaning plot, pencils, script,
lettering, inks. And altho we had begun our working relationship on that
book with Chris providing me with detailed, written plots, by issue 113,
when I started getting co-plotter credit in the book, we had switch
entirely to "phone plots". Chris and I would hash out the details over the
phone, then I would draw what we had worked out. (During the time
Roger Stern was editor, he was also in on this process, and Rog and I
would often talk on the phone ourselves, and frequently these
conversations would turn to the issue I was working on.)

As Chris and I had worked out the details for the original shape of what
came to be known as the Dark Phoenix Saga, Jean (Phoenix was still Jean
then, turned evil by Mastermind) flew off into space, had an encounter
with a Shi'ar ship, blew it up, and then returned to Earth. The Shi'ar
pursued her, and, in the original version, captured and "psychically
lobotomized" her. In this way, Dark Phoenix would be set up to become
a recurring villain in the series.

When it came time to draw the key issue, I, as co-plotter, decided Dark
Phoenix needed to do something "bigger" than just blow up a Shi-ar
ship. Something that would make it absolutely clear that Dark Phoenix
was the Meanest Mother in the Valley. So I decided to have her blow up
a star, and that that star would have at least one inhabited world in its
family of planets. I called Roger, ran this by him, and he approved. As I
recall, it was also Rog who suggested the "asparagus people", last seen
in AVENGERS 4. Chris liked this idea, too, and would subsequently name
them the D'Bari.

This, then, was an addition to the plot as Chris and I had originally
worked it out, not a "switcheroo".

If anything might be described as a "switcheroo" it was when Shooter --
who, by his own admission had "not been paying attention" -- saw the
pages and decided Phoenix had to be horribly tortured for all eternity for
her crime of planetary genocide. Despite the fact that this was no worse
than things we saw any of the top level Marvel bad guys do routinely
without any permanent consequences to be faced.

Another of the many ideas I deeply regret, given what happened with the
characters after I left!

But looking back, if I had the power, I would erase the whole thing. Too
many people since have, consciously or unconsciously, set the Death of
Phoenix as a scale against which to measure their own work. They want to
do their own "Death of Phoenix", their own "event", forgetting that what
Chris and I did was not planned as an event. It just happened.

   I could see what JB must be shooting at, realizing what the current generation of editors and creative types are doing with characters now.  It's one of the reasons that I'd feel like I'll never be a team player at places like Marvel or DC as they're being run these days.

The problem is all of the other readers who were inspired to be comic writers THOUGHT that they were good enough, but weren't! -Fan turned Pro syndrome.

They think that they're creating their own wonderful 'event' story but actually they're just wreckin' the good stuff.

Phoenix had to be tortured...

From reading Les Daniels' book on Marvel Comics, I got the impression that Shooter was appalled at the idea of a Marvel hero committing genocide. Did he not get that it was Dark Phoenix and not Jean who destroyed the planet?