Rehearsal dinner- maybe a stupid question

I would say yes to inviting them to the rehearsal dinner. If those groomsmen are bringing dates then the dates are "in for the weekend" anyway!

ETA: Would this be an "in town" or "out of town" wedding for the plus ones?

Honestly, I cannot imagine a casual date that would want to go to a rehearsal dinner, so cut them. Bridal party with sig others you know/long term partners, parents, sibling, your coordinator or officiant if they are going to be at the rehearsal.

That is it. It's really just a short thank you to the BP for rehearsing, not a stand alone mini wedding.

Not typically. Wedding rehearsal dinners are for the people that are needed to be at the rehearsal, their SO's (not the typical plus ones) and if you are being generous your OT guests.

If they want to bring them then I'd let them. FH's groomsmen all live 8 hours away so if any of them bring a date (only one is in a relationship at the moment) then of course their dates are invited to everything. Only one of my bridesmaids (local) is single and if she wanted to bring a date to the rehearsal dinner I wouldn't care.

If it was me I wouldn't. You want someone who you have never met to ne in your pictures?

We only had family and people who were part of the wedding, not casual dates.

We only have 2 single people in our bridal party, so we told them they could bring a plus 1. No one lives near our venue, so if they're bringing them to the wedding, I'm not going to ask that person to stay in the hotel alone while we all have a nice dinner.

None of my BM are married. Two are in relationships. I doubt any of them will bring a plus one (to wedding or RD), only because I am paying for their hotel (but they are rooming together) obviously your guy can't stay in a room with other women in a room I am paying for. So it will be an added expense that I doubt they want in addition to travel (which is the only thing they are paying for-everything else, dress, MUA, hair, hotel is covered by me). As far as the GM, all but 1 are in a relationship. I'm sure we will invite them all the bring their SO to the RD, but I am unsure if any will.

I've never been to a rehearsal dinner that included professional pictures.

OP, you don't need to invite them to the rehearsal dinner unless you want to and/or can afford to. The rehearsal dinner doesn't have to include plus ones, just significant others.

I'd say if they're OOT, you have to invite them-- who wants to be stuck in the hotel while their SO (even a recently met one) hangs out with friends, and since *that* is the case, I think you might as well invite all of them, even if you will never see these women again.

A plus one is standard etiquette. One of my husband's groomsmen had a date who wasn't his girlfriend and she came to our rehearsal dinner. I didnt mind as she was very nice and they were both staying at our hotel from out of town. I wouldnt have wanted him to leave her at the hotel so he could join the dinner.

I'd leave it up to the GM. If I was an in-town S/O of a GM, I wouldn't go. But if we traveled somewhere, I'd rather go than eat in the hotel or some random diner alone.