It seems they often stop laying when you change anything about their life. Some folks have birds that keep laying no matter what, but it seems most people have birds that need an adjustment period whenever anything changes. Adding new birds seems like a really likely reason. They have to...
Odds are that they are just settling in. The other thing it might be is a lighting issue. Did you have them with a lot of supplemental light when indoors and now they are getting less light? Maybe they think it is suddenly winter....
Did they stop when you moved them outside? How long ago was that? If they stopped when you moved them, then you know the answer to your question already. :) As long as the conditions are good for them, they will start again. Might take a few weeks.