No, I have not heard of that problem.
I am also using Team Foundation Server Source Control and I have not had any problems.
I have seen invalid expression shaped for other reasons, like getting Orch Instance ID’s, but not just because it was checked in TFS.
Do you have any policies in place or automated builds?
I thought I heard a while ago that BizTalk would have no support for FTS. Not sure if that’s true or not. Also not sure that no support means.
Please keep me updated on this.