The Tires and Wheels on the 1988 Buick Regal (and other GM-10 cars to follow) are not match mounted. A high point label or dot may still be on the tire, but it will not necessarily line up with the wheel's valve. Dealers should not dismount the tire to align this mark with the valve.
The reason the tire is still high point marked is because the same tire may also be used on other car models that are match mounted.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.