I get why you're concerned - he has form for bad judgements which have upset your dd in the past.
However. If that's the way it is, the BEST thing you could do for your dd is to try and make these times where he 'asks' a lot of her, easier for her. One of the best ways to do that would actually be to NOT react like this.
For example, the fact that you're focusing on the wedding and calling him an 'arsehole' for wanting to introduce his gf right then, is really not helpful! Your dd is going to pick up on that attitude - and it won't be long before she's a resentful little girl thinking 'arsehole!' about her own dad. Arsehole he may indeed be, but it's bad for her little mind to have to think that. Don't help her be that angry teen that doesn't respect her parent. It'll rebound on you too...
You don't have the power to dictate what he does (and nor should you) but you DO have the power to give your dd a nice strong, reasonable, laid back example to follow, which could really help her to frame her dad's actions in a positive light and thus feel better HERSELF about her relationship with him. You say she's anxious herself about the meeting? You could have chosen to comment that you're very happy that dad has a nice girlfriend at the moment, especially as we're all so happy because of the wedding coming up. Isn't it nice that Dad has someone to go out and have a nice time with too? You're meeting her this weekend? Oh that's handy, you can talk to her about the wedding. Sometimes it's hard to find things to talk about with a new person, but you can tell her about your dress and what the party will be like!
So - you see? Instead of communicating to your DD (even if you don't say it out loud) that this is all bad and stressful, you smile and say, great, that's nice, meeting new people is a good thing. You describe them as dad's girlfriend or friend and make it clear that these people aren't the equivalent of her stepdad, it's different, dad's CHOICE is to not have one special person that he stays with, but to spend time with people more as friends who go out and do things but might then decide to move on. Just like your DD sometimes does with her friends.
I really admire the way you've taken criticism on this thread and so I hope what I've said here will be helpful, I really think you could lead the way here on helping your DD take her dad in her stride a bit more as she gets older. After all - he's probably not going to change!
Good luck for your wedding!!!