Yes, it is a very good idea to acclimate the speakers to the room by leaving them wothout power for 24 hours before plugging in.
The reason is, that if they come from cold into a warm, humid living room, there is a risk of moisture forming on the film. When the panes is charges, it will start attracting dust particles in the air. If this happens while the film still has a small amount of moisture, there is a risk that the dust will attach more firmly to the film, with the result that high frequency performance is impaired. It can take quite some time (and countless vacuums) to get it back.
It happened to me when I bought my Vantages, and I know of one more case where the same thing happened. No permanent damage, but a lot of headache, plus one month being frustrated with poor performance.