That is only true for pre-1994 911s. The 928 never showed that behaviour due to having a Weissach axle from the very beginning of production in 1977.
The 928 and the 944 were also front engine with a rear transaxle, which evened out the weight distribution quite a bit, and that alone mitigated a lot of the lift throttle oversteer. I loved the handling of both of those cars...you get the 50/50 weight distribution of a mid engine car, but the handling is so much more stable and predictable because the weight is at the ends of the car. Too bad they were about as reliable as octogenarian flatulence.
I used to drive a 928. Perfect 50/50 weight distribution, beautiful throaty engine, and the most god-awful gearbox ever made. I had to rev match to shift up! in 2nd gear. They had a design flaw where the synchromesh just fundamentally would not work, and if you fixed it it would just break itself again.
I had to learn heel-toe shifting just to be able to drive that car at all. I fucking loved it, and it really got me into cars.
Also that car was great for whipping around a turn, just push on the throttle, slide around the back, then take off (I realize this is not the fastest way, but it is the most fun).
I apologize for the tangent, it's just not often people talk about 928s anymore.
https://www.youtube.com/watch?v=XiLc7GvmS_A
A 20 year old 944 was my first sports car. Simultaneously the best and worst decision I had ever made.
https://www.youtube.com/watch?v=8O8_FMhW9dY
"Porsche. There is no substitute."
I wonder what they paid for that line.
Funnily enough, that's exactly what you're supposed to do in a Porsche (assuming it is a rear engine 911). Unlike most cars, 911s will understeer (or correct an oversteer) when you mash the throttle, and oversteer when you lift off the throttle. The reason they're called widowmakers is that the oversteer/understeer dynamics are the exact opposite from what you would expect. Think you're going too fast into that turn? If you slow down, you're dead, but if you speed up, you'll survive.
It's also why crazy adrenaline junkies love them so much...in some senses, they're actually safer when you push them hard than they are when you try to be careful.