No, not really (sorry for getting your hopes up, Manglors fans!).
One of my favorite toys as a kid were Manglors. Made by Ideal in the 1980s, Manglors were rubbery figures, and the idea was you could tear off their limbs and then stick them back on. It didn’t really work out in practice–once you’d torn off the limbs and re-assembled them, they looked pretty sad and were never quite the same. It’s the sort of toy that lasted maybe a week.
Memories of those toys came to me today when I saw Mattel’s pics of Swamp Thing’s articulation, with noticeable tearing at the wrist.
Of course, this is (presumably?) a prototype, so it’s hard to know whether this will be an issue with the production figure. Mattel’s track record has most fans assuming it will be, though.
On a side note, a lot of people are already comparing this to DC Super Heroes Clayface. I must admit to having never encountered any problems at all with my Clayface (knock on wood)–after plenty of display and posing, both of my figure’s arms are dark and there is no tearing. Perhaps I just got a really good one.