Life is ever changing--and quickly. Mobile phones have gone from "bricks," to celluars so small you almost had to move them back and forth between ear and mouth just to have the speaker and microphone in the proper place at the appropriate moment, back to something larger that can accommodate easy texting. Televisions have gone from huge consoles that could emit only black-and-white, to thin, high-def, mega-sized models that can wall-mount...and now, the latest is to watch movies on a teensy phone screen! Yes, everything changes, and a writer's writing ought to, as well.
I see a number of submissions where it's obvious the author wrote the manuscript a decade ago. That's not a bad thing. There's nothing wrong with pulling out an old manuscript and dusting it off, polishing it, and submitting it--but there is something wrong if the editor or agent to whom you send it can tell it was written in a bygone "contemporary" era.
I'm not talking about an individual and unique voice. Your writing should always be "you," but it should also demonstrate an ability to capture a perfect sense of time and place. For example, it wouldn't do in a contemporary to have your heroine stranded and not be able to call 911 unless it was clear that she didn't have a cell phone for some plausible reason or that phone was inoperable.
This evolution doesn't apply only to prop devices, but also to emotional and plot content, and to dialogue. Writers need to adapt to the changing trends in their genre. Today, it is not only more accepted, but necessary, to include a deeper emotional pull in a Christian novel whereas twenty years ago, most stories were deeply plot-driven with the focus being more external than internal.
Dialogue choice can be a dead-giveaway to an "old" manuscript. Contemporary speech is always changing. Slang changes. These things, if not updated, can alert the editor, agent, or reader that the manuscript isn't current.
So, if you're pulling out an old manuscript to polish and submit, remember to look not only at the technical issues in which your skill has improved over the years, such as point-of-view and passive writing, but also to anything that might date the story--from a public phone to no emotional content, to speech patterns that are no longer "contemporary." Doing so may be the difference between contract and rejection.