If you list products on surfaces across Google standard listings, all products must be in stock. Products that are out of stock will be disapproved, as per Google’s latest policy update.
If too many products are out of stock, new products become preemptively disapproved, even when they are in stock. To avoid this from happening, check the different solutions below.
Usually, the preemptive disapproval triggers if 10% or more items are out of stock.
As of writing on the 16th of October 2020, I can not find any cases this policy is enforced, however, this may change soon.
There are two options to avoid disapprovals.
Option 1: Excluded Destination Attribute
You can add the value Surfaces across Google to the attribute excluded destination.
This can be achieved using the following 3 methods.
A) Feed Rules
Create a feed rule, if product availability is out of stock, set excluded destination to Surfaces across Google
B) Supplement Feed
You can create a supplement feed with Google Sheets. The only two columns you need is id and excluded_destination. Than add your product id in the id column and the value Surfaces across Google in the excluded_destination_column
C) Data Feed Source
Depending on the data feed solution you have, you can apply the values here too. For example if you use the FeedArmy APP, you can use an automated import rule, as with Google Merchant Center, to set the excluded destination value when items are out of stock.
Option 2: Submit a unique feed
A little overkill, but it is possible to submit a unique data feed for surfaces across Google only. And only include in stock products. With FeedArmy you can create multiple feeds, one for Shopping Ads, Shopping Local Inventory Ads, Surfaces across Google, etc.