There has been a rash of dual pane glass quality problems (mostly fogging) in RVs made from around 2002 to 2010, particularly those from SEGI (whom I think went out of business as a result). But they weren't the only one with problems. I has dual pane in a 1996 or 2002 coach with no problems at all, but my 2004 started getting window fog in 2008 and now have 5 windows afflicted with them. I'll be repairing/replacing this winter if the budget permits. Hard to say if newer Rvs will have the same problem now that the issue is known and suppliers changed, but ther movement & vibration of an RV is hard on the seals between the two panes of glass, so the risk is there all the time.
I'm not convinced that dual pane RV windows have much positive benefit anyway. Some, to be sure, but none of my RVs have been very resistance to noise and heat gain/loss despite having dual pane glass. I think it's a rather small thing when considered among other selection criteria.