Yes. Old star bolts can and do fail, and seeing existing star bolt plates on a Philadelphia rowhome does not mean the wall is currently stabilized.
The most common failure modes are: corrosion of the steel rod reducing its cross-section and load capacity; loosening at the interior anchor plate due to wood shrinkage or joist movement; and failure of the masonry around the exterior plate where brick or mortar has deteriorated.
Philadelphia rowhomes with pre-1970 star bolt installations may have used smaller-diameter rods or interior anchor methods that do not meet current standards. Visible signs of potential failure include rust staining from the plate, fresh cracking in the brick around the plate, a visible gap between the plate and wall surface, or continued bowing.