I mean, I would actually say that Clone Wars' storyline of Maul surviving and turning into a crazy junkyard spider was a bit too silly tbh, but as long as he's here, doesn't it make sense to end his story? They're going to tell Darth Maul's last moments at some point to close out that storyline, why is that actual story finally coming up 'milking it'?
I don't understand what the difference for you is with Maul being in Clone Wars and him being on Rebels. It's still made by largely the same team, and his story never really got to a close on Clone Wars. Honestly sounds more like your distaste for Rebels and admiration for Clone Wars that's the problem here. I personally never really cared for Maul as a character, but, having brought him back to life in the cartoons, it makes too much sense to bring that story to it's natural conclusion. To the point where it'd be a shame if they never got to it.