Matthew to Replace Mark?
An article by David C. Sim, "Matthew's Use of Mark: Did Matthew Intend to Supplement or to Replace His Primary Source?." New Testament Studies, 57, pp 176-192
Most scholars acknowledge Matthew's debt to Mark in the composition of his own Gospel, and they are fully aware of his extensive redaction and expansion of this major source. Yet few scholars pose what is an obvious question that arises from these points: What was Matthew's intention for Mark once he had composed and circulated his own revised and enlarged account of Jesus' mission? Did he intend to supplement Mark, in which case he wished his readers to continue to consult Mark as well as his own narrative, or was it his intention to replace the earlier Gospel? It is argued in this study that the evidence suggests that Matthew viewed Mark as seriously flawed, and that he wrote his own Gospel to replace the inadequate Marcan account.
That the author of Mt made much use of Mk indicates a degree of acceptance I presume Sim also mentions this point, I'll peruse the article next visit to college.