The malware was only found on the IdeaPad series (their consumer line). From reporting on it, the management team is separate from their business (Thinkpad) line, and the malware came from the 3rd party software packages that were included to subsidize the production of the low-end lines.

Those 3rd party packages are not a concern for the Thinkpad lines, since the higher business price point supports the lines without the need for subsidizing.