App objects (this file) are just used for interactions with items on the page so a property that just returns an html element doesn't really fit into the model.

To make it fit the model you could make this property `first_predictive_word_a11y_role` and then just refer to this property directly in the test. It trades off some verbosity in the app object for keeping the test itself clean and readable.
Same goes for methods that do a11y click, for example:
https://github.com/mozilla-b2g/gaia/blob/master/tests/python/gaia-ui-tests/gaiatest/apps/lockscreen/app.py#L67