Re: is my husband wrong?
Sonia, your husband probably wants some independence, it's natural. You shouldn't dismiss his needs and certainly do NOT put your perception of your MIL's needs above his.
There is a way round this, sit with him and LISTEN to him, see if you can get him to tell you his reasons calmly by NOT challenging him on this need to move out.
Then you should come to a compromise, e.g. agree to move out after a year perhaps? This will give time for the wedding to come and go, time for his parents to adjust etc.
As for you worry as being seen to be the instigator of this, you should both sit down with the in-laws WELL AFTER they return and discuss it together. Your hubby can tell them his reasons and clear u.
You can always visit and stay over there whenever you want.
It's not worth ruining your relationship with your husband for the sake of your MIL, even though it is good that you get on, mashallah.