Same thing happens on my Note 10.1 2014 and my Galaxy S3.
My Nexus 7 2013 does keep the file type default app. The setting to clear out is under the application itself in application manager. You would have to clear the "Launch by default" setting under the application. Obviously this doesn't apply to our device since the default app never saves.
:Current Android Devices:
Samsung Galaxy S4 [VZW, Rooted Stock 4.4.2 deodex
Samsung Galaxy Note 10.1 2014 SM-P600 [Stock]
Nexus 7 2013 FHD [Rooted Stock]