[70Sixter]

The simplest answer is that all the Porsche "approvals" have expiration dates. Oil companies can request extensions.

The more complex answer is that things change. One would hope for proper technical, physics-based reasons.

Then: My Box came with recommendations for synthetic SAE 10W-40, 15W-40 or 15W-50 above 50 degrees F.

10W-40, 10W-30 or 5W-30 for below 50.

API rating SH or SJ. ACEA A3.

Now: It is 0W-40, 5W-40, or 5W-50. (I'm using 5W-40.)

API SH is now listed as "obsolete" on the API website, and even Porsche has approved oils with as low as API SM on the previous list. (I have not checked the new list for API ratings, and won't until my next oil change.)

From my study: API SL should be considered minimum, and SH or SJ preferred. And ACEA A3 or B3.

Additives for engine life like ZDDP have been reduced in recent formulations. Some say because they can damage cat converters and, by inference, the environment.

The current and previous approval list only specifies brands and viscosities. API and ACEA rating require research for each listed oil.

Does The List matter? Not a lot unless your car is under warranty. I do believe it is valid for the viscosity requirements.