The function indeed is for adding default WooCommerce Views functions to be used for WordPress Views plugin wpv-if (nowadays wpv-conditional) statements, along with woo_product_on_sale(), woo_product_in_stock(), wpv_woo_single_products_rating_func()
These methods also automatically appear in Views Conditional Functions supported area in the Toolset Settings, so they can be used in conditionals.
There is even an example usage in the code:
[wpv-if evaluate="woo_product_in_stock() = 1"]
Stock is available for this product.
[/wpv-if]
[wpv-if evaluate="woo_product_in_stock() = 0"]
Stock is not available for this product.
[/wpv-if]
That's exactly as you apply it too.
But wpv-if, or wpv-conditionals do NOT listen to AJAX events, as explained previously.
Whether or not the function would actually display updated data, the HTML conditions do not listen to any "on the fly" change.
They only apply what comes from the server, when the page is loaded, not when it's modified with later scripts or events.
If you only want to display the out of stock, or other native WooCommerce messages related to the stock, then there are ways to achieve that, but displaying messages conditionally after some changes done with AJAX or JS in an HTML condition is not possible.
That does not execute as JS, it executed already as PHP at this moment.
You can try this easily, make an HTML condition that listens to whichever data you can alter with JS on the front end.
Making changes won't affect the condition, only after reloading it with that data it'll affect the condition.
This is different than in Toolset Forms Conditions, which are responsive by nature to changes on the fly.
The out of stock displayed by WooCommerce should instead be displayed by using Toolset's ShortCodes for the add to cart and choose options:
https://toolset.com/documentation/user-guides/views-shortcodes/#woocommerce-views-2, https://toolset.com/documentation/user-guides/views-shortcodes/#vf-154367
The HTML conditions will not respond to AJAX, but only to page reloads.
So if once the produce is actually out of stock (all of it, not just single variations), then it will display the out of stock part as set in your HTML condition, but only after a full reload of that page.
Concluding, there should be nothing broken so far.
Can you solve the issue on your end by using the ShortCodes we provide for the handling of stock (and other) message handling?
If not, a custom JS solution should be created, as a conditional display with AJAX is not possible using HTML conditions like this.