Is the Seventh Circuit correct in its view (contrary to that of other courts of appeals) that a district court may, in response to a motion made pursuant to Federal Rule of Civil Procedure 12(b)(6), "effectively grant summary judgment" under Federal Rule of Civil Procedure 56 without providing plaintiffs their procedural rights under Rule 56, on the basis that Rule 12 and Rule 56 can "merge"?

Is the Seventh Circuit correct that a district court may 'effectively grant summary judgment' under Rule 56 without providing plaintiffs their procedural rights, on the basis that Rule 12 and Rule 56 can 'merge'?