I just tracked a bike ride and . . . it worked! The map is there and HealthFit transferred it right over to Strava, GPS and all.
Did Apple maybe send out a hot fix or did I just get lucky somehow?
I actually had started my watch activity by accident, and then when I realized, I started Strava. Then I went back to the native watch app just to see, and it was off. I restarted it, and then went back to Strava, which told me I could only have one watch app tracking my activity at a time. So I left Strava off, figuring I should test again. But I doubt that sequence has anything to do with my success.
Anyway, I had tested since my full restore of both watch and phone, and it hadn't worked. But today, it did.
Edit: just checked activities from last week before I noticed the problem, and they are still stuck with just the one location flag.