I mean, why not? since Order Stat Jewels already exists, that is basically Stat+Damage (even though it's only limited to Somberholt) also, they've done it before with gems.... remember Reinforced Blood/Fire/Glacial gems (Stat+Armor) and Eye of Syrillax (Stat+Crit)?

However I don't like the idea of fusing jewels. Maybe they can find new ways to introduce these hybrid jewels for future content?