That's probably about it. But your earlier point, about conservators being frustrated by wildly impermanent materials, is also true. Sadly for them, though, that kind of frustration is just part of the job. Ever since the 50s or so when artists started using these materials, it became the museums job to deal with them as best they could. They knew better than to try to dictate what artists use.

But I'm sure they're thrilled when something shows up that's not only an important piece of art, but will last for a while too. It's a lot of work (and money) building a collection. The thought that at least some parts of the permanent collection have a chance at being permanent must be a relief to these guys.