When we sold our home in 2016, the inspection noted that there was no GFCI for protection for the kitchen outlets. House was built in 1978-79 time frame.
So I ordered a GFCI breaker for the electrical panel online, only to find that area of the home had two circuits with a common neutral, so I could not use a panel GFCI breaker. I installed a GFCI outlet(one that allows downstream outlets) at the lead outlet and let it protect the other kitchen outlets.
So this issue of share neutral is not a new one. Any 240V appliance that also needs a 120V circuit is wired the same way.