Kay

You wrote:”But how can we justify such an interpretation that is simply based on hypothesis or guess

Mark,

Well reasoned interpretations about verses are made all the time
– obviously none of us were there when they were written and the original human writers are no longer available for consultation, so there is no other choice.

As I pointed out (in #149) Paul has no unchanging iron-clad rules about widows and their remarriage requirements that pertain to all younger widows, in all places, for all time.