Will we need M# to maintain and further develop in the future?


You will not have to.

We have always been aware of this valid concern of clients. That's why in designing M# we have made sure that there won’t be any dependency upon M# in the generated code.

Of course you can use M# on an ongoing basis to benefit from its productivity and quality benefits. But it's reassuring to know that if one day you decide to move away, your ownership or ability to maintain and further develop your .NET project will never be compromised.