Meaning of 说话人最可能 **是** 什么关系？ 是,有

Would you please let me know if in this sentence "说话人最可能 是 什么关系？", we can use 有 instead of 是 to be read as:

说话人最可能 有 什么关系？
Heavily dependent on the context, I guess it means 说话人最可能**(和谁)**是什么关系？ (omitted some words). The 谁 should refer to someone (or something) mentioned right above. Check the context.