I like Jeff Popes statement the best regarding this issue. As it has already been stated; todays NEC would not allow this installation practice but as again Jeff stated so well…today is not yesterday !..well I basically said what Jeff said and put my own spin on how I said it…
If the circuits in question are protected properly by a correctly sized overcurrent protective device then you should be fine. The fact you stated that the bathrooms had GFCI’s then one suggestion may be to replace the older GFCI’s with newer models with more assurances of reliable operation than older GFCI models.(I will leave it at that).
However, as stated by others; in the event you update the house a properly training, licensed and insured electrical contractor can update your electrical system as deemed needed.