It’s total bullshit. There is no hint to whatsoever. It’s Star Wars, not Dallas.

To be clear:

Rey is Sabine’s daughter ? No hint;
Sabine is Obi-Wan’s dauther ? No hint.

There is a dark saber ? Yep, Maul was a former ruler of Mandalore, he kept an artifact as a souvenir (he basically says it !). Sabine picks up the dark saber ? Yep, she’s a mandalore, she knows what it is, that’s all ! Maul wants to find Obi-Wan ? No big deal: Ben is his oldest ennemy, he wants revenge, it wasalready the topic of the previous episode he appeared in.

Average episode, better than the previous Maul’s one; but the season stays very weak compared to the first one and even to the second one. It’s time they finish it.

edit: i’m talking about the last episode. Some say the so called “hints” will be contained in the january episode (Ghost of Geonosis II). I really hope not (Rey being a Kenobi would be such a bad idea).