Hi,
Thank you for reaching out. Please find my response to your questions below:
As mentioned in the blog post, starting from April 17, 2020, app ads and app engagement ads that do not serve will have their statuses changed automatically from ENABLED to DISABLED. So for the specific query you are using, you would get all statuses including ENABLED as you do not have any condition in your query.
The number of rows might be affected if and only if it is the App Campaign and some of the ads are automatically changed from ENABLED to DISABLED as they stopped serving and you specified in your predicates to only return the ENABLED ads.
I hope this helps. Please let me know if you have any further concerns.
Thanks and regards,
Xiaoming, Google Ads API Team