Moving will be made to interrupt spellcasting at a point in time...

[Nikita]

Cancelling spell casting when moving will be pretty useful on fights like Ifrit where you need to move out things on the ground, if they implement it correctly... Looking back, I remember the skill for CON that was listed on the official site, which allowed CON to cast spells while moving for a set amount of time, so I imagine this was the plan all along. No complaints here!

[Zeref]

Cancelling spell casting when moving will be pretty useful on fights like Ifrit where you need to move out things on the ground, if they implement it correctly... Looking back, I remember the skill for CON that was listed on the official site, which allowed CON to cast spells while moving for a set amount of time, so I imagine this was the plan all along. No complaints here!

I distinctly remember a time where moving a certain distance from your spot would result in canceling the cast a long time ago, i think it just got swept under the rug with the combat reforms going on.