The much-loved sitcom is returning to BBC One after a long absence with a special on Christmas Day.
“There’ll be some people who go, ‘Oh, it’s not what it used to be’ – that’s just the law of averages”, Jones, 53, who also plays Nessa, told the Radio Times Christmas edition.
“However, I’m sure people will just enjoy seeing those characters again and spending Christmas with them.”
She and co-creator James Corden, 41, and the rest of the cast have created a group on WhatsApp which “will start going nuts” when the show airs, the pair said.
Corden, who also plays Smithy, told the magazine: “Making this Christmas special, from the moment we put the first Post-It note of the story up on the wall, to the moment we called wrap on the shoot, to the edit, to being on Facetime at four in the morning doing edit notes with Ruth, every single moment of it has been an absolute thrill.
“I wouldn’t change a single second, so all we can do now is put it out into the world and hope that people respond to it.
“And if they don’t – we still wouldn’t change a second.”
The pair said they only had around 24 hours in total to write the pilot script, back in 2005 – but two weeks to pen the special.
LA-based Corden will be back in Britain for Christmas Day, with his wife and their three children.
Asked if he will watch the Queen’s Christmas Day broadcast, The Late Late Show host said: “I’m a fan but not militant about it. I mean, if lunch overruns, or lunch starts late, which actually is more accurate… but it’ll be an interesting one this year.”
Gavin & Stacey stars Mathew Horne and Joanna Page as a young couple who fall in love following a whirlwind romance.
The show features a strong supporting line-up of memorable characters, including Rob Brydon’s eccentric Uncle Bryn and Alison Steadman’s over-protective mother, Pam.
The full interview is in the Radio Times Christmas issue out now.