I honestly have the same fear right now, which is why I'm still waiting on the game. Seeing people talk it up as a resurgence of old-school JRPGs, having a great demo, and bragging mostly about the artstyle and combat gives me pretty bad Bravely PTSD. Yeah I know it's a different team and all...but I'm still hesitant about making the same mistake three times (yeah I decided to try Second too...was better than the first but not by much).
Still...I'm not completely attached to my bias...if people start completing the game and still feel the same positivity, I'll probably give it a shot. Though with my RPG backlog this year...I'm not really in a hurry either.
I'm not exactly in a hurry, while definitely not last year, I've a decent backlog for the rest of the year, not to mention I'm just off the back of Nier: Automata and am doing New Game+ in Persona 5, and am currently awaiting the Xenoblade 2 DLC campaign. In other words I'm not at a dire need for JRPGs.
If I'm being perfectly honest, part of the reason I'm so interested in this, beyond the combat system and art style, is that I want more significant third party support on the Switch, but haven't actually done much towards that effect. Of my 6 Switch games, only one is third party, and it's Shovel Knight. While Shovel Knight's great, I REALLY don't need to worry about Yacht Club's future games coming to Switch. Third parties like Square Enix, Ubisoft, Bethesda, etc., are much more of a concern.