A customer that specifically chooses Proton for privacy, must read and agree to privacy policy, which explicitly states, that Proton may in fact keep temporary IP logs and that user may opt in for login IP logs. Requests from authorities may ask for this kind of information and Proton will have to provide it.
The „opt-in“ part for login logs is particularly interesting, because in fact Proton recommends this as a security best practice. Whether it’s in the best interest of the customer or not, it’s an open question. I would say, in a risk model, where threat of human rights violation by Swiss government is much lower than risks of unauthorized party accessing the account, it makes sense. Tough luck for the criminals that followed this advice.