It would be my understanding that, the flowers are no use to you now. When you transplant, they will likely drop off from transplant shock. I'd remove them personally. Fruit likely is not your biggest concern at the stage they are currently at.

Many discussions here about this the search will pull up if interested but the common consensus is just leave them alone. The plant will automatically drop most of them all on its own and the few it doesn't drop will either make it for early production or die off at transplanting. But the choice is ultimately yours to make. Try it both ways for a good learning experiment.

Dave

You are already taking them out? I'm south of you and other than a few weeks ago, my highs have been in the low 60s at best. Isn't that too cold?

My rule of thumb lately is that if they are in pots, and not yet planted out, pinch them off. Before tomatoes are planted out, they sure don't need extra stressors like fruit production. No energy is being expended on flowers. The energy that would be expended is if those flowers turn into fruit. I can't see any value in having fruit on plants in temporary pots. I guess one could say, just as well, to just pinch fruit.

Boris, I've been hardening mine off for a week or so now despite the cold. Forgot them one night and it got down to 49. They survived. They're outside full time now (unless we get close to frost temp) until I can get the beds ready. This rain and cold has set everything back.

Tomatoes will survive just fine down into the 30s. They just won't grow in low temps. You don't want pollination or fruiting to happen at temps below 50F, however.

I prefer to wait (for most warmth loving crops really) until the night time temps are at least above 50-55 consistently, and daytime above 70, usually after Mother's Day here. I can plant a little earlier, and if we don't get any late frosts I could get away with late April many years, but things just sit there until the weather warms. It all does best for me in mid May.