Is it possible to change the wiring gradually?

Hello! We are going to make repairs in the apartment in which we live permanently. We will repair the kitchen and bathroom. The master suggests that we replace the wires in the kitchen and bathroom and bring this cable to the machine, to the shield. The entire apartment is now wiring old, Soviet, aluminum. That is, after his work, the wiring will be replaced in the kitchen and in the bathroom, the rest of the apartment will remain old. Since we cannot dismantle all cabinets and prepare the entire apartment for wiring replacement, can we agree to his proposal and change the wiring partially without connecting new wires to old ones? Can we then also partially replace the wiring in each room and eventually get new wiring throughout the apartment?