There's God Wars for the Switch now if you wish to replay that, Mercenary Saga Chronicles, Mario and Rabbids, Disgaea 5, and the three Banner Saga games. In a few weeks, Valkyria Chronicles 4 comes out, which hopefully will be good. Of the set out currently, I'd go with The Banner Saga games first.
some more titles :
Ambition of slimes
Nobunaga's Ambition 15 (more historical strategy than tactical? )
Unreleased (but this thread will still be visible later) :
Disgaea 1 complete [Oct 2018]
Magic Scroll Tactics (2D sideview, but still tactics)
Fire Emblem Three Houses 
Valkyria 4 has a playable demo is you want. [2019 sept 2018]
We had a previous console's "RPG list thread", maybe one for switch could be created too. 3DS rpg list DS rpg list
Switch RPG List, anyone?
I was playing Valkyria 4's demo the other day, and it is looking good.
Just download it for free on the eShop and check if it is your cup of tea.
I think it is coming in September 25th, so... less than a month.