It was not a surprise that everyone who purchased a Soultrait Symbol wanted to have it upgraded as much as possible. Michael accepted their wishes, but he decided to send Kraft Viton to negotiate the contract terms instead of doing so by himself.
Michael did that because he wanted to show everyone that he trusted the Bartholomew Corporation and used Kraft Viton as his manager. At least, that was Michael's intention since he was pretty sure that Kraft Viton was a much better negotiator.