The clip being referenced: Miley looks at Animal's chain and remarks "Nice bling" to which Animal roars "Bling BLING" - so not only is it a gag about how Animal is the intimidating creature that he is that he has to be chained, but his line is a remark to something said to him (delivered in that Animal-flirt-with-WO-MAN manner!) so that doesn't bother me in the least as opposed to just some random use. It's all about context.
Agreed it is all about context, not like Piggy's "I gotta Pee" comment in MFS, she didn't NEED to say that for any reason, it didn't fit in. In this case, there is a context.
They do look a bit awkward though, i think its them having been dressed up in all the cutesy costumes that makes it seem that way. I hope it doesn't come off as the original Muppets using all these hip words and doing hip stuff and not being themselves.