Almost certainly the answer. Same reason they just hobbled their "ok Google" by not letting you access it with the screen off anymore. They're going to switch engines and they want to reintroduce the same features all over again but make it feel like an upgrade.
"We can't remember what happened last quarter, so surely our users won't remember how their phones used to be better! Genius! Moving on, time to go make and destroy a new app, how about a notepad app this time?" --Google