I agree with BigBerthal. You said, “yes she wants to move” - if she were my friend of 30 years I’d definitely say something!! I’d point out that 1) when people are in their mid 70’s they prefer to be closer to family, 2) she’s putting physical as well as emotional distance between them and their children, 3) ask if are they going to be flexible and always travel back to family for holidays (can’t make a move like that and NEVER, EVER expect family to drive that distance for a day), 4) can they house family that do come and stay overnight in the new bungalow or at a hotel, 5) will they have resources for care or shelter in an emergency, 6) as above, if help is needed for the simplest of tasks, household repairs or assistance, are they prepared to pay for services that sons were helping with in the past (errands, lawn care, removal of air conditioners, smoke detectors)?
These are factors that might not have been considered but taken for granted in the past. How are they REALLY going to spend their time plopped in an entirely new community? The grass isn’t always greener and she may resent him for urging this move….Good luck!!