I'm not implying a deep spiritual connection, I'm just interpreting what I have at hand. What I'm saying is that there's something there. An analogy.
And I can't fight your bringing up outside or real-world facts, which aren't really relevant to understand the show. Especially who's married to whom and alike. I agree it gives you extra laughs, but in the end, in a hundred years, in two hundred years if this show still has at least one viewer, that viewer will care about the episodes, and will interpret the episodes by their intrinsic value, not whether they were inspired by this or that.
I don't know whether he would have married a crossroads chick. That's a speculation, and since it's all aired, you may never know. I know I saw a woman in S4 and the same woman in S6. If it were a book, I'd make a parallel. It has a meaning in the overall plot of the show, it builds up on their relationship from S4, so why not? I hope I'm not overthinking it, but I think you're "underthinking" it, belittling its symbolism, so to say, to prove your point.
It's kinda like during season two I noticed a vintage red and white truck parked outside the roadhouse a lot and then outside the place where Sam was kidnapped by the demons.
I thought it MIGHT be something as of yet it was just they had a limited number of trucks and cars to put out for filming and they reused the same one on two locations by chance.
Not everything means something (espcially in tv with budget limitations and so forth), sometimes it's just a matter of saving money, convience, or whatever.
In this case they were wanting to reflect the real world (or something close to it) and it just so happened that JP was married to the chick who played Ruby so they played up on that for laughs. That's all it really was.