Tempering of alloy steel

Alloy steels are steels that are alloyed with different elements such as nickel, chromium and phosphorus to improve mechanical properties such as hardness, durability and heat resistance. I'm quite interested in alloy steel because different alloy elements can do different things to the material. And of course, the amount of the alloying elements is important, too.
So now I was wondering if all alloy steels can be heat-treated. I have a hard time imagining that every alloy steel can be hardened in the same way, as I am sure that some types can not endure high temperatures due to the properties of the alloying elements. For example, on the website https://www.edelstahl-haerten.de/en/materials/ I couldn't find all the austenites under the list of materials qualified for the heat treatment. And in contrast to the ferrites, there was no '....' that indicated that there were any more materials than they had listed there. Can someone explain ?