Anyway, Time Mage right now as a job would be now impossible to introduce, given the current spells distribution among the rest of the mages. It's the type of job which should have been introduced from the beginning, or in the first expansions, since right now they would either be not unique at all and remove many "defining" spells from other jobs, or be too bizarre just in order to make them different enough.

Also, Meteo(r) isn't Time Mage exclusive: in FFIII it was Black Magic. In FFIV was Black Magic too (only Rydia and Fusoya could use it). FFV, the game of the job's debut, was Time Mage exclusive. FFVI has no real jobs and anyway everyone could learn it so doesn't count. FFVII is a plot device. FFVIII is in the same situation as FFVI. FFIX is cast by Vivi, THE Black Mage. In FFXII is Exodus' final attack, so no job correlation. FFT, also known as the greatest game of all time, gives Meteor to Time Mages. In FFTA 1 and 2, It's an Alchemist spell.

So, tl;dr version: Athough it's a spell used by several characters/classes, if anyone has the right to claim Meteor's ownage, it's BLM.