The Taliban is making promises, yes. We have yet to see if they will turn out to be empty or not. Immediate signs are that it is business as usual for girls in schools in Afghanistan (oh, except I heard a report of headscarves being handed out). In other words so far they seem to be coming good on their word but it is still very early days, in the middle of a transitional period, and our understanding of what is happening all over the country is quite limited, so who knows?
As much as their word might be in doubt (apparently) I don't think its a good tactic to refuse to say to the Taliban, yes educating girls, that is a good thing. (I got called something nasty for saying just this.) We want to encourage the Taliban to stick to the committment they made, to come good on it if you prefer, and that's not going to come by threatening to bomb them all over again (that hijab bloke said something like this recently... he can be okay sometimes) or refusing to talk to them because they are the incarnation of pure evil (or whatever the latest agitprop has everyone thinking). Or maybe you can suggest a better way to encourage the Taliban to pursue education for girls?
As to full and complete education there's a severe lack of schools for even basic education in Afghanistan right now. Many children are missing out - 8 000 more schools needed is a figure I've seen in the media though what that equates to in numbers of children I'm not sure. (As an aside the other major correlation for teen pregnancy is poverty.) And that is predominantly an economic problem. International aid would be one solution but maybe you can think of another?
And yes various people did say specifically that it was useless/irrelevant to educate girls if they are just going to end up married off young.