the fares does not have to be repriced after the outbound is flown, correct, however the fare rules still apply (combinability, flight application etc etc) so does the min/max stay which is always stricter rule. otherwise you could always buy a 1 month ticket and exchange afterwards your inbound to another date so that your stay is - let's say - 5 months. If so, who would buy 12M tfares where you pay for a 12M fare on in- and outbound.

i agree with you that penalties/changes do apply as per fare component - at least on EK tickets.

Same story if you look at the cancellation fee - also stricter rule, doesn't matter if you have flown the outbound or not (despite that the "cancellation after departure" fee is applicable).
if the outbound fare is non-refundable and the inbound is full refundable and maybe a 400usd fee after departure, the ticket will still be non refundable (theoretically you can take the non-refundable part on an EMD and use it for another ticket but this is another story )

maybe you are lucky and the agent does not get it that the original ticket is only valid for 1M (he/she will notice later when they get an under collection from HQ)