This isn't for general tyres. It's for the OEM size no matter which brand you use.
In simple words, it's saying to increase the tire pressure in case of high speed driving. This is opposite to what people in Pakistan do. They usually decrease tire pressure for motorways which is one of the main reason for tire burst on motorways in high heat.
For motorway, at least keep 32 psi. Even 1 psi more is better than less. The reason for this is tire with low pressure run hotter. It gets deshaped at high speed and there's no space between the threads for the air to pass.
People who drive on German autobahn are instructed to increase 0.5-1.5 psi for every 10 kph speed increase