So after Kenobi was previewed in the rebels mid season trailer I had a few questions. Will Maul make it out of there next fight? I think yes. Because we see maul is powerful still at this point by killing all them inquisitors. But the next time we are recorded to see Obi-Wan fighting in A New Hope he sucks. He not as fast or strong as he once was and has less stamina. However he is still smart. That is something Maul never has been, Maul is arrogant.
Next what is bringing him back going to achieve? killing Maul? But Maul hasn't done much except make Ezra more aware and trained in the dark side, so killing Maul now would make his return pointless and prove it was all fan service. Besides it would be better for the plot if Ezra overcame his inner darkness and killed Maul, destroying any links to the dark side.
So what if Obi-Wan trains Ezra for a short period of time. This could coincide with Kanan training Sabine (also in trailer) and could help to develop Ezras skills even more.