I honestly don't feel like there is ANY negative aspect at the back end of that contract. I don't know exactly when people started thinking players at 34-35 years old are anathema, but I think that's a little extreme. Ekholm is a rock solid citizen for us, and I have no qualms whatsoever keeping him for 3 more years, no negatives whatsoever. And really, if we're rebuilding/retooling we are never going to be desperate for Cap space in that time. So who cares. Keep the ones that we brung to the dance, he's a proper Pred.
That said... yes, I would ultimately accept Broberg and a 2nd. I think Broberg is the more key asset to push for in such a trade than any 1st. He has size, skating, he's a little gentle, but there is a good player in there who we could transform into a top-4 D for us. Saving 10+ years on age is also attractive, even though it will take a little luck for him to ever hit Ekholm's level. But we have entered that era, it seems.