After Miller's 2001 sequel BATMAN: THE DARK KNIGHT STRIKES AGAIN 1-3 that were universally panned, I'm surprised he's attempting another sequel (or two possibly).

Actually, I'm one of the few who liked many elements of the 2001 series, although not as good as the first.

I think it's a bad idea for Miller, or any artist, to come back and do a sequel long after-the-fact. I've yet to see a revival by any creative team that held the slightest comparable quality to the original series. Especially decades later, when an artist is working in a sharply different style than they were 10, 15, 20, 30 years ago.

For me, it comes across as an exploitative attempt to make money off the former series' popularity, by an artist who did his best work many years ago.
The Miller Batman stuff.
The WATCHMEN sequels.
Neal Adams' new Batman stuff.
Roger Stern's much later Hobgoblin series, roughly 20 years after his AMAZING SPIDER-MAN run.
Englehart/Rogers' 6-issue series that followed up their classic DETECTIVE COMICS 471-476 run.
Michelinie/Romita Jr/ Layton's IRON MAN miniseries, back around 2001.

And worst of all, Jack Kirby's HUNGER DOGS.
If the artist or collaborative team continued the series just a few years after they did the first, where they could continue it with the same style and vision, then maybe.
But so far after the fact, it seems obvious they don't even remember what they originally envisioned, and it's a whole new beast when they finally try to continue it.

One that I liked, warts and all, was the continuation of the McGregor/Russell AMAZING ADVENTURES/KILLRAVEN series (issues 18-39), when it was continued in the KILLRAVEN graphic novel (in 1983). And even continuing the series just 7 years after the series ended in 1976, there were still annoying differences in style, to both story and art.

As much as I would love to see continuation of so many of these series, so long after the fact, you just can't go home again.