Gubernator is correct. If Corky obtains a 717 type rating on the commercial certificate, it will automatically be given ATP privileges upon passing the ATP practical test in the same category and class of aircraft. It is NOT necessary to pass a checkride in that particular type.
For example, if a pilot holds a 717 type on his commercial certificate, but passes the ATP checkride in a 737, the ATP will show type ratings for both the 717 and 737. That pilot will hold ATP privileges in both the 717 and 737. This occurs automatically, without additional paperwork or a separate request.
14 CFR 61.157(d):
"Upgrading type ratings. Any type rating(s) on the pilot certificate of an applicant who successfully completes an airline transport pilot practical test shall be included on the airline transport pilot certificate with the privileges and limitations of the airline transport pilot certificate, provided the applicant passes the practical test in the same category and class of aircraft for which the applicant holds the type rating(s). However, if a type rating for that category and class of aircraft on the superseded pilot certificate is limited to VFR, that limitation shall be carried forward to the person's airline transport pilot certificate level."