In the 1770’s it was not unusual to send young children (ages 10 to 12) to Europe for schooling (William Smith, for example) or, like William Temple Franklin, for someone to spent almost their entire adult life in Europe. If they were original born in Virginia and had children while in Europe, their children would be citizens of Virginia, even if the children grew up in Europe.
Obviously, if it could be shown that they were active loyalist that could affect their claim.
It's really rather simple and no long winded diatribe is necessary.
If I may ask something of your hypothetical situation...which side of the war did the man fight for?
And if he didn't actually fight which side did he support?
I'm trying to see whether or not you realize that such a situation as you present, especially in the time frame you've presented, has a direct effect on the children due to their parent's, and most notably their father's, allegiance.
Your question is a "set up" for the unwary or uninformed, plain and simple, without further information to make a determination.
Could affect their claim? How about WOULD determine their fate.