N.,
I am a teacher at a MDO program and have read several responses to your question which is very legitimate and I applaud your concern over the matter.
As a teacher I would say consistency is best especially in a shcool wide setting. The reasons why the blankie is not allowed during class time most likely are:
1. Blankies and such security items are very important for the children and when you allow one child to bring it in, then ALL the children want to bring in their "security" item. Some of these are not necessarily blankets. When trying to teach, they cause distractions.
2. Lost items. When you have a lot of children in a classroom and they want to lug their stuff, it often gets misplaced and lost. You then have another problem because then if it gets lost, you are the one out of luck at night time at home. I have 19 children in my class and can not keep up with all their belongings. I teach 4-5 year olds and sometimes they can't keep up with jackets and lunch boxes.
3. Rules - You need to respect the rules your MDO lays out. I am sure this is a director wish and not the teachers in the classroom, so therefore they are following what their boss wants. Your two year old is trying to battle you so that "he" can win. If you do not work with the teachers and pull him out, then he knows he got his way. Two year old are very smart and know what they are doing. It will then set you up for more battles down the road with your child thinking if he cries he will get his own way.
He can understand that only "nap" time is he allowed to have his blankie. You can tell him that his blankie is in his backpack all the time. Perhaps the teachers could hang his blankie somewhere so it is in sight. I like the idea of cutting a piece to put in his pocket but he would need to know that he can't pull it out.
The teachers are trying to be consistent with all their children in the classroom, so if one child brings something in, then all the kiddos would because parents would not view this as fair - and it wouldn't be.
I hope this helps somewhat from a teacher's point of view. It is also very hard for teachers to not allow children to bring in their things when they are crying but we know it is best in the long run if we don't give in.
M..