One of the columns you see in the Requests tab where all your requests are listed is the More filters> Requests status column. here I'd like quickly go over the statuses you see for your requests.
The requests will have this status as long as they are still sold out.
When you restock the Awaiting stock requests the notifications will be sent and the status of the requests will be changed to Restocked.
When you have the GDPR feature enabled all your request statuses will be Pending GDPR first and if the customer consent to receive notifications from your shop it will be changed to Awaiting stock. you can more about it in this article.
Except for the Premium plan, all the other plans have a notifications limit. for example, you can send 10 notifications per month in the free plan. (you can see them all in the Plans section in your panel). imagine you restock an item or different items that have more than 10 notifications. in this case, since you have a 10 notification limit 10 of the requests will be sent but the rest will not and their status will be changed to Pending Upgrade. if you then upgrade your plan or wait until your next cycle your notifications will be sent to your customers.
That is all to it. you can filter these statuses with the Status option.
You can then have actions on just some specific requests. like send manually all the awaiting stock requests or delete all the pending GDPR requests.